Tuesday

July 28, 2015

July 28, 2015

Total # Posts: 1,878

**math**

recall that speed is distance travelled per unit of time, or v = d/t substituting, 80 = 84.2 / t 80t = 84.2 t = 84.2/80 t = 1.0525 h hope this helps~ :)
*April 26, 2011*

**Math**

x^2 - x = -2 can be rewritten as x^2 - x + 2 = 0 observing, the given equation is not factorable, thus we use the quadratic equation: x = [-b +- sqrt(b^2 - 4ac)]/(2a) where a = numerical coefficient of x^2 b = numerical coefficient of x c = constant substituting, x = [ -(-1...
*April 24, 2011*

**algebra 1**

recall that the equation of a circle is given by (x-h)^2 + (y-k)^2 = r^2 where h = x-coordinate of center of circle k = y-coordinate of center of circle r = radius thus from the given equation, (x-2)^2 + (y+4)^2 = 9 the radius is sqrt(9) = 3 also, recall that area of circle is...
*April 24, 2011*

**Math**

36x^3 + 53x^2 + 38x + 35
*April 24, 2011*

**geometry**

recall that surface area of rectangular prism is given by SA = 2*(LW + LH + WH) where L = length W = width H = height substituting, SA = 2*[(8)(5) + (8)(2) + (5)(2)] SA = 2*(40 + 16 + 10) SA = 2*(66) SA = 132 in^2 hope this helps~ :)
*April 18, 2011*

**Geometry**

recall that the diagonal of a cube is given by d = sqrt(3*s^2) where s = length of side of cube substituting, d = sqrt(3*6^2) d = sqrt(108) d = 10.39 = 10.4 in hope this helps~ :)
*April 16, 2011*

**Science**

(1) True (2) False
*April 16, 2011*

**Science**

liquids and gases
*April 16, 2011*

**chemistry**

to get the number of He atoms, we dive the given mass to the mass of each He: 1.0 / (6.65 x 10^(-24)) = 1.50376 x 10^23 He atoms hope this helps~ :)
*April 16, 2011*

**chemistry**

first we write the chemical reaction: Al + HCl -> AlCl3 + H2 then we balance it: 2Al + 6HCl -> 2AlCl3 + 3H2 also we need to look for the masses of Al. from the periodic table, Al = 27 g/mol therefore, 54 g Al * (1 mol Al / 27 g Al) * (3 mol H2 / 2 mol Al) = 3 mol H2 or ...
*April 16, 2011*

**chemistry**

recall that molarity is just moles of solute per liter of solution, or M = n / V first we convert the 400 mL to L: 400 mL = 0.4 L substituting, M = 0.4 / 0.4 M = 1 M hope this helps~ :)
*April 16, 2011*

**More Solutions Chem**

first we balance the given chemical equation, thus: 2NaOH + H2SO4 -> Na2SO4 + 2H2O note that we need to balance a chemical equation because we need their stoichiometric coefficients (number before the chemical formula of a compound or element) to make ratios. since we are ...
*April 15, 2011*

**Chemistry**

first let's see if the chemical equation is balanced. Zn + HCl --> ZnCl2 + H2 since not yet balanced, then we balance it :P Zn + 2HCl --> ZnCl2 + H2 since we are given grams of Zinc, we need to find the mass of Zn from periodic table to convert it to moles. thus Zn...
*April 15, 2011*

**algebra**

*reposted* first note that we can't combine radicals if the radicands (term inside a radical sign) are not equal. notice that we can further simplify squareroot of 45 as sqrt(45) = sqrt(3*3*5) = sqrt(3^2 * 5) = 3*sqrt(5) now, we can combine them: 3*sqrt(5) + 4*sqrt(5) 7*...
*April 15, 2011*

**algebra**

first note that we can't combine radicals if the radicands (term inside a radical sign) are not equal. notice that we can further simplify squareroot of 45 as sqrt(45) = sqrt(3*3*5) = sqrt(3^2 * 5) = 3*sqrt(5) now, we can combine them: 3*sqrt(5) + 4*sqrt(5) 7*sqrt(5) hope ...
*April 15, 2011*

**Chemistry **

2C2H6 +7O2 --> 4CO2 + 6H2O since this is already a balanced equation, we can now use their stoich coefficients for the ratios. first, since we need grams of CO2, we find it's molecular mass. from the periodic table, the masses of C and O are C = 12 and O = 16 , thus 1*...
*April 15, 2011*

**algebra**

*reposted* first note that we can't combine radicals if the radicands (term inside a radical sign) are not equal. notice that we can further simplify squareroot of 45 as sqrt(45) = sqrt(3*3*5) = sqrt(3^2 * 5) = 3*sqrt(5) now, we can combine them: 3*sqrt(5) + 4*sqrt(5) 7*...
*April 15, 2011*

**Algerbra**

(x+2)(x+4) = 30 + x first we expand the left side of the equation,, multiplying them, x^2 + 2x + 4x + 8 = 30 + x then we combine similar terms and make the right side of equation equal to zero (since it's quadratic equation) : x^2 + 6x + 8 - 30 - x = 0 x^2 + 5x - 22 = 0 ...
*April 15, 2011*

**help please**

yes. if you're using MS Word, first highlight the text you want to double space, then right click and choose 'Paragraph' . you will see at the bottom right, 'Line Spacing' , and from there choose 'Double'. hope this helps~ :)
*April 15, 2011*

**math**

yes, it's linear equation in 3D. notice that e^2 + ln(2) looks complicated, but it's actually just a constant.
*April 15, 2011*

**calculus**

you're welcome~ :) by the way, i just want to make a correction. fro the value of V and SA, it's not 100, it should be 100*pi = 314.16 . sorry i forgot the pi, because i cancelled it right away, but the answers for r and h is still the same. i'll just retype the ...
*April 15, 2011*

**calculus**

sorry i haven't replied to your reply earlier. anyway, here's an example: there are many possible examples for this. but since we need to calculate volume (V) and surface area (SA), we choose a figure where its V and SA can easily/readily be calculated. for instance we...
*April 15, 2011*

**calculus**

yes :) do you want me to cite an example?
*April 15, 2011*

**MATH PLEASE HELP!**

or you can also make it 1 by dividing it by itself : 9-4.2) / (-4.2) = 1
*April 15, 2011*

**MATH PLEASE HELP!**

what do you mean "make -4.2 a one" ? is it something like you express -4.2 as sum of two number where one of them is 1 ?
*April 15, 2011*

**math**

distributive property~
*April 15, 2011*

**algebra**

first we represent the unknown using variable, let x = pounds of nuts needed then we set up equation. since we are given the number of pounds of raisins and its price per pound, we'll multiply it to get the total amount of the 12-lb raisins. we do the same for the the nuts...
*April 15, 2011*

**Math**

first we represent unknowns using variables, let x = the number of students asked then we set up the equation,, since the given were the fractional parts of the total number, we represent each part as (1/6)x : the number of students who like math (2/3)x : the number of ...
*April 15, 2011*

**Math**

first we represent unknowns using variables, let x = the number of students asked then we set up the equation,, since the given were the fractional parts of the total number, we represent each part as (1/6)x : the number of students who like math (2/3)x : the number of ...
*April 15, 2011*

**Algebra**

4x + 5x = 180 9x = 180 x = 20 substituting, 4x = 4*20 = 80 degrees 5x = 5*20 = 100 degrees hope this helps~ :)
*April 14, 2011*

**algebra**

9*9*8*7*6*5*4 = 544320 ways
*April 14, 2011*

**Chemistry: Stoichiometry**

first we write the combustion reaction: C6H12O6 + O2 -> H2O + CO2 then we balance it: C6H12O6 + 6O2 -> 6H2O + 6CO2 since mass of glucose is given, we get its molecular weight,, from the periodic table mass of each element in glucose is H = 1 , C = 12 , O = 16 6*12 + 12*1...
*April 14, 2011*

**Chemistry: Stoichiometry**

*i'll just repost my answer~ :) first we write the combustion reaction: C6H12O6 + O2 -> H2O + CO2 then we balance it: C6H12O6 + 6O2 -> 6H2O + 6CO2 since mass of glucose is given, we get its molecular weight,, from the periodic table mass of each element in glucose is...
*April 14, 2011*

**math**

since it's factorable, 2u^2 + 5u - 18 (2u + 9)(u - 2) hope this helps~ :)
*April 14, 2011*

**math**

since it's factorable, 3u^2 - 11u - 14 (3u - 14)(u + 1) hope this helps~ :)
*April 14, 2011*

**chemistry**

to get the heat released or absorbed, Q = mc(T2-T1) where m = mass of substance (units in g) c = specific heat capacity (units in J/g-K) T2 = final temperature T1 = initial temperature *note: units of temp doesn't matter if it's in degree Celsius or Kelvin, as long as ...
*April 14, 2011*

**physics**

oops, scrap my first answer,, i forgot to convert 35 km to meters: 35 km = 35000 m substituting, 51.6 * 10^(-3) = -3.31*( 11.7 - T1 )/(35000) 0.0516*35000/(-3.31) = 11.7 - T1 -545.62 = 11.7 - T1 -557.32 = -T1 T1 = 557.32 deg C sorry~ ^^; hope this helps~ :)
*April 14, 2011*

**physics**

recall that for an energy transfer, q = -kA * dT / dx where q = rate of heat tranfer (in Watts) k = thermal conductivity (in W/m-K) dT = differential change in Temperature (in Celsius or in Kelvin) dx = differential change in position (x-direction) *note: this is negative ...
*April 14, 2011*

**Geometry**

recall that when lengths of diagonals are given instead of base and height of a rhombus, we can still calculate it's area using the formula A = (1/2)*(d1 * d2) where d1 and d2 are lengths of the diagonals. substituting, 1326 = (1/2)*(39 * d2) 2652 = 39 * d2 d2 = 2652 / 39 ...
*April 14, 2011*

**Geometry**

recall that area of triangle is just A = (1/2)(bh) where b = base h = height since we need to find the height, thus the given AC is the base. substituting, 494 = (1/2)(19)*h 988 = 19*h h = 988/19 h = 52 inches hope this helps~ :)
*April 14, 2011*

**Math**

first, we get the volume of each solid. for the cube, recall that volume is just V = s^3 where s = length of a side substituting, V,cube = 2^3 = 8 in^3 for the rect. prism, recall that volume is just V = l*w*h where l = length, w = width, h = height substituitng, V,prism = 8*6...
*April 14, 2011*

**chemistry**

to get the heat released or absorbed, Q = mc(T2-T1) where m = mass of substance (units in g) c = specific heat capacity (units in J/g-K) T2 = final temperature T1 = initial temperature *note: units of temp doesn't matter if it's in degree Celsius or Kelvin, as long as ...
*April 14, 2011*

**math/115**

let n = any real integer. the absolute value of n, or | n | , means you always get its positive value. for example, | 2 | = 2 |-5 | = 5 | 0 | = 0 thus for -|-618| , we first get its absolute value, then multiply by -1 : -|-618| = -(618) = -618 hope this helps~ :)
*April 14, 2011*

**algebra**

let's write the old and new equations: (i) 6x+3y=12 (ii) 6x+3y=36 notice that they have the same slope, thus the new line (ii) is parallel to the original line (i). also , transforming this into slope-intercept form, they become (i) y = -2x + 4 (ii) y = -2x + 12 the y-...
*April 14, 2011*

**Math**

work backwards. first we start with -34. from the second statement, it was said that she doubled it, but since we're working backwards, we divide -34 by 2: -34 / 2 = -17 then subtracted by 12,, thus we add 12 by -17 : -17 + 12 = -5 multiplied by -5,, thus we divide by -5...
*April 14, 2011*

**chemistry**

at STP (standard temperature and pressure: T = 0 deg C , P = 1 atm), one mole of gas occupies a volume 22.4 L . or to you can derive this one using ideal gas law: PV = nRT where P = 1 atm (STP) T = 273.15 K (STP) R = gas constant = 0.0821 L*atm/mol-K n = 1 mol hope this helps~ :)
*April 13, 2011*

**8th grade math**

observe that we can factor xy from (x^2)y + x(y^2): (x^2)y + x(y^2) + x + y = 100: xy [ x + y ] + x + y = 100 then we can factor (x + y): (x + y)(xy + 1) = 100 since xy = 9, (x + y)(9 + 1) = 100 (x + y)(10) = 100 x + y = 10 getting its square, (x + y)^2 = 100 x^2 + 2xy + y^2...
*April 13, 2011*

**MATH URGENT!!!!!!!!!**

both can't be simplified further~
*April 12, 2011*

**calculus**

x-intercept is a point on the curve where it crosses the x-axis, thus y = 0. substituting, y = 2x^3 + 2 0 = 2x^3 + 2 0 = x^3 + 1 0 = (x + 1)(x^2 - x + 1) thus the only real solution is x = -1 ; and the x-intercept is at (-1, 0) for the second question, when the numerical ...
*April 12, 2011*

**physics**

recall pressure is force per unit area, or P = F/A where the force is in Newton (N) , pressure is in Pascal (Pa) and area is in square meters (m^2) thus, we first convert the dimensions to meters: 19 cm = 0.19 m 27 cm = 0.27 m A = 0.19*0.27 = 0.0513 m^2 substituting, 100000 = ...
*April 12, 2011*

**grade nine math **

from the 2nd line, when -35 is transposed to other side, 15r - 35 + r = 3r - 9 15r + r - 3r = 35 - 9 ...it must be positive 35. you forgot to change its sign.
*April 12, 2011*

**Math**

since we don't see the figure, but know that two consecutive angles of a parallelogram is supplementary (sum is equal to 180 degrees), 180 - 70 = 110 degrees (measure of angle F) hope this helps~ :)
*April 12, 2011*

**chemistry**

Fe2O3(s)+3CO(g)--->2Fe(s)+3CO2(g) we see that this chemical equation is already balanced. to get the number of moles of CO, we multiply the given moles of Fe2O3 by the stoichiometric ration from the balanced equation,, thu 1.75 mol Fe2O3 * ( 3 mol CO / 1 mol Fe2O3 ) = 5.25 ...
*April 11, 2011*

**math**

1/4 of 48 means you multiply 1/4 by 48. 1/4 * 48 note that we can rewrite 48 as 48/1 since any number divided by 1 is equal to itself. thus rewriting, 1/4 * 48/1 to multiply fractions, we multiply numerator by numerator and denominator by denominator. (note: numerator-the ...
*April 11, 2011*

**maths**

h t t p : / / w w w . w o l f r a m a l p h a . c o m / i n p u t / ? i = y % 3 D x + a n d + y % 3 D x ^ 2 - 6 x - 1 0 ..without the spaces~ :)
*April 11, 2011*

**algebra 1**

you forgot to multiply 20 by 8: n+8(n+20)=110 must be n+8n+160=110 but you're on the right track~ :)
*April 11, 2011*

**math**

first we represent unknowns using variables,, let x = first number let x+2 = second number note that since they are consecutive but both even numbers, the difference between them is 2, that's why the second number is x+2 now we set-up the equation,, since the sum of the ...
*April 10, 2011*

**math**

first represent unknowns using variables,, let x = first number let x+1 = second number note that the second number is x+1 because they are consecutive numbers. now we set up the equation,, according to problem, their product is 240, thus: x(x+1) = 240 x^2 + x = 240 x^2 + x - ...
*April 10, 2011*

**math**

first we represent the unknowns using variables,, let x = width let 3x-3 = length (according to the first statement) now we set up the equation,, since we are given the area, recall that the area of a rectangle is A = L*W where L=length and W=width. substituting, 90 = (3x - 3...
*April 10, 2011*

**elementry algebra**

since this equation is already in the slope-intercept form, we can readily determine the slope and y-intercept. note that in slope-intercept form , y = mx + b, m is the slope ; and b = y-intercept thus in the given equation, y = 2x + 2 m = 2 ; and b = 2 since y-intercept is a ...
*April 10, 2011*

**math**

for (1), a^2 * b^(-3) note that when a term is raised to a negative exponent, we get its reciprocal and raise it by the positive exponent,, for example, 2^(-4) = 1/(2^4) ; thus we can rewrite b^(-3) = 1/(b^3) therefore, a^2 * (1/(b^3)) a^2 / b^3 for (2), (5/3)^-3 we do the ...
*April 10, 2011*

**chemistry**

assuming the gas is ideal, we can use the formula, P1*V1/T1 = P2*V2/T2 where P1 = initial pressure V1 = initial volume T1 = initial temperature (in K) P2 = final pressure V2 = final volume T2 = final temperature (in K) we first convert the given temp to Kelvin units: T2 = 12...
*April 10, 2011*

**Calculus**

ahh i think i know why y = (a+b)/2 is wrong,, it's actually the MINIMUM, not the maximum~ ^^; i tried assigning some values to the variables,, and from the graph, rate -> infinity at y -> inifinity , or at a finite value of a and b, when the reaction is at completion...
*April 10, 2011*

**Calculus**

for (a) since a < b , for a certain value of y , the value of (a - y) will become negative first, and thus the Rate becomes negative,, then after some time (b - y) will become negative too, and the Rate becomes positive. let's look at some points: at 0 <= y < a , ...
*April 10, 2011*

**jordan high**

umm i think in the problem, you mean "the volume DECREASES",, assuming the gas ideal, we can use the formula P1*V1 = P2*V2 where P1 = initial pressure V1 = initial volume P2 = final pressure V2 = final volume *this equation is Boyle's Law substituting, 0.63 * 324...
*April 10, 2011*

**calculus**

antiderivative = integral to get the integral of this, note that we can rewrite (cos x)^3 as (cos x)(cos x)^2 . then recall that (cos x)^2 = 1 - (sin x)^2 ,, rewriting: integral of [ (cos x)(1 - (sin x)^2) ] dx then we let u = sin x ; and thus du = cos x dx substituting these...
*April 9, 2011*

**Algebra**

x + (1/6)y = 1/2 to transform this into y = mx + b, first we isolate the y term into the left side of equation,, thus the x on the left side must be transposed to the right side. to do this we change the sign of x to its opposite (positive becomes negative): x + (1/6)y = 1/2 (...
*April 9, 2011*

**maths(urgent....please...)**

hello arun~! i think i also answered this yesterday,, i'll just re-post my solution here. if there's something you didn't understand, feel free to ask. :) first we observe that the motion of the ball is projectile and its trajectory (path followed by the ball) is ...
*April 9, 2011*

**Math**

you mean (7x^2-18x-7)/[(x-4)(2x^2-6x+3)] ? if so, it cannot be further simplified.
*April 9, 2011*

**algebra**

note that you cannot combine radical terms if their radicands (the terms inside the radical sign) are not equal. for example, sqrt(8) + sqrt(18) you cannot add them right away since 8 is not equal to 18,, thus we first simplify each term. for sqrt(8), note that we can rewrite ...
*April 9, 2011*

**Physics**

note that voltage is constant across each resistor. also in parallel circuit, the sum of the currents across each resistor is equal to the total current,, since there are only two resistors in the circuit in the problem, I1 + I2 = I,total substituting, 1 + I2 = 3 I2 = 3-1 = 2 ...
*April 9, 2011*

**math**

recall that speed is distance travelled per unit time, or v = d/t since the given speed is in miles per hour, we first convert the given time (the 12 minutes) to hours: 60 minutes = 1 hour ; thus 12 minutes = 0.2 hour substituting, v = d/t 35 = d/0.2 d = 7 miles hope this ...
*April 8, 2011*

**physics**

recall that I = V/R where I = current (in Amperes) V = voltage (in Volts) R = resistance (in Ohms) substituting, I = 6.7/70 I = 0.0957 A hope this helps~ :)
*April 8, 2011*

**algebra**

let's put parenthesis so that it's not so confusing: (x-1)/(x-9) - (x+1)/(x+9) + (x-153)/(x^2-81) first we get the least common denominator (LCD) of these,, observe that (x-9)*(x+9) = x^2 - 81 . thus the LCD is equal to x^2 - 81 . multiplying all terms by (x^2-81)/(x^2...
*April 8, 2011*

**Physics**

recall that speed is distance traveled per unit time, or v = d/t also recall that work is force exerted times distance, or W = Fd since in the problem we are only given the force, we calculate for the distance first. substituting the given speed and time to formula for speed: ...
*April 8, 2011*

**Chemistry 1001**

note that gases are more soluble in higher pressures, thus CO2 gas will be most soluble in 900 torr. i think the most common example (observation) for this is when you open a carbonated drink,, before it is opened, CO2 gas is dissolved in the liquid. when you open the bottle, ...
*April 8, 2011*

**Maths**

first we represent unknowns using variables,, let x = number of boys let y = number of girls according to first statement, ratio of boys to girls is 3:2 or 3/2 . thus we can write, x/y = 3/2 or x = (3/2)*y according to second statement, there are 11 more boys than girls, thus...
*April 8, 2011*

**math**

first we represent the unknowns using variables: let x = length according to first statement, the width is 1 more than half the length,, thus let (1/2)x + 1 = width now we set up the equation,, since we are only given the area, we can use this to solve for length and width. ...
*April 8, 2011*

**algebra2**

y = 8*(3^x) recall that domain is the set of all possible values of x,, here there is no restriction for x thus the domain is all real numbers. recall that range is the set of all possible values of y,, here note that y cannot be negative since the term 3^x is always positive ...
*April 8, 2011*

**math**

y = x^2 + 2x - 15 y = (x - 3)(x + 5)
*April 8, 2011*

**chemistry**

assuming the gas is ideal, we can use the formula, V1/T1 = V2/T2 where V1 = initial volume T1 = initial temperature (in K) V2 = final volume T2 = final temperature (in K) we first convert the given temp to Kelvin units: T1 = 7 + 273.15 = 280.15 K T2 = 15 + 273.15 = 288.15 K ...
*April 8, 2011*

**Math!!!!!!HELP!!! :(**

kilogram is a unit of mass while gallon is a unit of volume. you can relate them by using density of a particular substance (density is mass per unit volume or d = m/V) for example, if we consider water, which has a density of 1 g/mL or 1 kg/L, and recalling that 1 gallon is 3...
*April 8, 2011*

**math**

do you mean how many hours will it take for the feeder to give all of the food he/she is holding? if so, then we first convert 3 kg to grams: 1 kg = 1000 g ; thus 3 kg = 3000 g now we divide 3000 by 150 to get the time needed: 3000 / 150 = 20 hours hope this helps~ :)
*April 8, 2011*

**math**

recall that speed is distance travelled per unit time, or v = d/t since they are travelling towards each other, we add their speeds (since travelling towards each other consumes less time for them to meet than travelling in the same direction) substituting, v = d/t 610 + 618...
*April 8, 2011*

**MATH VERY URGENT!!!!!!**

first we observe that the motion of the ball is projectile and its trajectory (path followed by the ball) is shaped like a parabola. the horizontal distance travelled by the ball is thus given by: R = (vo)^2 * sin (2*theta) / g where R = range or the horizontal distance vo = ...
*April 8, 2011*

**science**

to get the heat released or absorbed, Q = mc(T2-T1) where m = mass of substance c = specific heat capacity T2 = final temperature T1 = initial temperature **note: if Q is (-), heat is released and if (+), heat is absorbed now we can only apply this to substances that did not ...
*April 8, 2011*

**MATH URGENT!!!!**

for (a), we substitute 17 to d in the equation for the height,h: h = -0.045d^2 + 2d h = -0.045*(17^2) + 2(17) h = 20.995 yards for (b), we are given the height and we need to find the horizontal distance. substituting, h = -0.045d^2 + 2d 8 = -0.045d^2 + 2d 0 = -0.045d^2 + 2d...
*April 8, 2011*

**calculus**

observe that we can further simplify (|x+h|-|x|)/h to (x + h - x)/h (h)/h 1 rewriting, lim 1 as h->0 at x = 4 is equal to 1, since the limit of a constant is also equal to that constant. hope this helps~ :)
*April 8, 2011*

**Physical Science**

to get the heat released or absorbed, Q = mc(T2-T1) where m = mass of substance c = specific heat capacity T2 = final temperature T1 = initial temperature **note: if Q is (-), heat is released and if (+), heat is absorbed now we can only apply this to substances that did not ...
*April 8, 2011*

**chemistry **

assuming that the gas is ideal, we use the formula for ideal gases: PV = nRT where P = pressure (in atm) V = volume (in L) n = number of moles R = gas constant (0.0821 L*atm/mol-K) T = temperature (in Kelvin) we first convert the 26 degrees Celsius to Kelvin: 26 + 273.15 = 299...
*April 8, 2011*

**geometry**

since the lengths of sides of the flag are equal, the shape of the flag is a square. recall that the area of square is A = s*s where s = length of a side of square. substituting, A = 60*60 A = 3600 square cm hope this helps~ :)
*April 8, 2011*

**chemistry **

assuming that the gas is ideal, we use the formula for ideal gases: PV = nRT where P = pressure (in atm) V = volume (in L) n = number of moles R = gas constant (0.0821 L*atm/mol-K) T = temperature (in Kelvin) we first convert the 26 degrees Celsius to Kelvin: 26 + 273.15 = 299...
*April 8, 2011*

**MATH URGENT!**

first we observe that the motion of the ball is uniformly accelerated motion (because of acceleration due to gravity while it's in the air), thus we use this formula to find time: h = ho + vo*t - (1/2)*g*t^2 where ho = initial height vo = initial velocity t = time g = ...
*April 7, 2011*

**geometry**

recall that area of trapezoid is A = (b1 + b2)*(h/2) where b1 and b2 are the bases of trapezoid h is the height substituting, 4 = (b1 + b2) * (1/2) 8 = b1 + b2 now we list two number whose sum is 8: 1 and 7 2 and 6 3 and 5 4 and 4 these are the possible lengths of bases. hope ...
*April 7, 2011*

**Math**

hmm,, recall that when we consider a parallelogram, we also consider square, rhombus, and rectangle (they are all parallelogram) now, let's analyze each choices: for (a), it's only true for a square. for (b), it's true for square and rectangle. for (c), it's ...
*April 7, 2011*

**algebra**

do you mean, 13/18 divided by 20/27 ? if so, then we first get the reciprocal of the divisor (the second term; that is, 20/27) ,, thus its reciprocal is 27/20 (note that reciprocal is just interchanging the numerator and denominator) now the process becomes multiplication. to ...
*April 7, 2011*

**geometry**

first represent unknowns using variables: let x = length of rectangle let x-6 = width of rectangle (according to first statement of problem) now we set up equation,, since in the problem we are given the perimeter, we can use this to set up the equation,, recall that perimeter...
*April 7, 2011*

**math**

triple 4 means 3 times 4: 3 x 4 = 12 since we subtract 2 from 12 each day , we need to divide 12 by 2 to get the number of days needed to reach zero: 12 / 2 = 6 days hope this helps~ :)
*April 6, 2011*

**Math 8th Grade**

there are many possible answers here. one answer could be the length of longer = 14 m and shorter = 9 m it can also be longer = 18 m and shorter = 7 m .. i think you forgot an information in the problem,..
*April 6, 2011*

**Algebra **

yes
*April 5, 2011*