Monday

July 6, 2015

July 6, 2015

Total # Posts: 1,869

**Math**

to do this, first we know that there are 18 ways for the first place (since there are 18 dogs), then 17 ways for the second place (18-1=17 since no dog can win two places), and 16 ways for the third. thus, we multiply these to get the number of ways: 18*17*16 = 4896 ways hope ...
*April 4, 2011*

**Math**

to do this, first we multiply the 1st terms or the number with no exponent (not the terms with 10 raised to an exponent). thus: 4.3*2 = 8.6 now we multiply the 2nd terms,, recall that if they have the same base (here, the base is 10) we can simply add the exponents: 10^3 * 10...
*April 4, 2011*

**Math**

to get the total weight, we multiply them: 2x10^(-5) * 1x10^15 to do this, first we multiply the first terms or the terms with no raised exponent,, thus that would be the 2 and 1: 2 * 1 = 2 next we multiply the second terms or the 10 raised to exponent,, to do this, recall ...
*April 4, 2011*

**Geometry**

to do this, we calculate both of the circles' circumference. the bigger circle has diameter of 26 in, while the smaller has diameter of 18 in. now recall that the circumference of a circle is given by C = 2*π*r or given the diameter, C = π*d where π = ...
*April 4, 2011*

**math**

when an object is dropped from a certain height, it is a freefall. when in freefall, the only external force acting on the body is gravitational force (neglecting air resistance). the motion of the object is unformly accelerated motion: (v2)^2 - (v1)^2 = 2*g*h where v2 = final...
*April 4, 2011*

**math2**

first, we list the factors of each number,, 15: 1, 3, 5, 15 34: 1, 2, 17, 34 55: 1, 5, 11, 55 since the only common factor among them is 1, the greatest common factor (GCF) of the numbers is 1. hope this helps~ :)
*April 3, 2011*

**math**

first, we convert 9 Liters to milliliter,, recall that 1 L = 1000 mL, thus 9 L = 9000 mL now we divide 9000 by 90 to determine how many 90 mL-bottle she needs: 9000 / 90 = 100 bottles hope this helps~ :)
*April 3, 2011*

**chemistry**

you need a periodic table of elements. in the periodic table, you can find certain properties of elements and and also atomic number and atomic mass. since in the problem, we are required to calculate for molar mass of H2O, you look for H and O in the periodic table and get ...
*April 1, 2011*

**Chemistry**

first write the balanced chemical equation: C3H8 + 5O2 -> 3CO2 + 4H2O **note: in combustion reaction of organic compounds, the usual products are carbon dioxide and water. then calculate for molecular weight of propane (the C3H8),, Carbon is 12 while H is 1: 3*12 + 8*1 = 44...
*April 1, 2011*

**physics urgent please **

an example of projectile motion would be the motion of the baseball when it is hit by the bat,, it the trajectory (the path followed by the object) has the shape like a parabola. projectile motion is possible because of gravity. about the velocity, since it followed a path ...
*March 31, 2011*

**algebra **

domain is the set of all possible values of x, while range is the set of all possible values of y. for example, y = x^2 since any values of x can be substituted here, we say that the domain is all real numbers (zero, positive and negative numbers -- any number actually ) while...
*March 31, 2011*

**math**

x squared is usually typed like this: x^2 (means x raised to two) :) anyways, the given in y = x^2 - 6x - 8 and we need to find x when y = 1. thus we substitute y into the equation: y = x^2 - 6x - 8 1 = x^2 - 6x - 8 now to solve for x,, first we make one side of the equation ...
*March 31, 2011*

**Math**

we can also rewrite this (a+b)squared=64 as (a+b)^2 = 64 first we expand (a+b)^2 (a+b)^2 = 64 (a+b)(a+b) = 64 a^2 + 2ab + b^2 = 64 since we are given the value of ab, which is ab = 3, we can substitute it here: a^2 + 2(3) + b^2 = 64 a^2 + 6 + b^2 = 64 a^2 + b^2 = 64 - 6 a^2 + ...
*March 31, 2011*

**math**

that 'n' is actually the Greek letter π which is equal to 3.1416... but since in the problem π = 22/7 , we use this value. recall that the area of a circle is given by A = π*r^2 where r = radius substituting, A = π*(7^2) A = (22/7)(49) A = 22*7 A = ...
*March 31, 2011*

**Algebra**

since it's 30 by 30, the shape is a square. recall that the diagonal of a square is given by: diagonal = sqrt(s) where s = length of a side thus, the diagonal is sqrt(30) hope this helps~ :)
*March 31, 2011*

**math **

if the given sequence is a geometric sequence, then it follows the formula A,n+1 = r*(A,n) where r = ratio between two consecutive terms A,n = the nth term A,n+1 = the term after A,n substituting the first and second term, 40 = r*16 r = 40/16 r = 2.5 to check, let's see if...
*March 31, 2011*

**physics**

recall that pressure is force per unit area or P = F/A first of all, we convert 10 cm^2 to m^2 for consistency of units (since the unit Newton is actually kg*m/s^2),, therefore 10 cm^2 (1 m / 100 cm)^2 = 0.001 m^2 substituting, P = 180/0.001 P = 180000 kg/(m*s^2) = 180000 Pa (...
*March 31, 2011*

**math**

(fog)(x) = f(g(x)) = [g(x)]^2 (fog)(x) = [sqrt(x-3)]^2 note that the sqrt and ^2 will just cancel each other out: (fog)(x) = x - 3 to find its domain,, recall that domain is the set of all possible values of x,, since we both considered f(x) and g(x) here, we find the ...
*March 31, 2011*

**math**

(gof)(x) means you substitute the whole expression of f(x) to g(x): (gof)(x) = g(f(x)) = f(x) + 1 (gof)(x) = x + 1 for #2, we do the same,, we substitute f(x) to f(x): (fof)(x) = f(x) (fof)(x) = x hope this helps~ :)
*March 31, 2011*

**math**

first we can actually substitute f(x) by y, thus f(x) = 3 - 5x y = 3 - 5x to get the inverse, interchange the x and y variables,, thus x = 3 - 5y now, we solve for y: x = 3 - 5y x - 3 = -5y y = -(x-3)/5 then we substitute back f(x) to y, but this time since we get its inverse...
*March 31, 2011*

**math**

(fog)(x) means you substitute the whole function of g(x) into the f(x),, we can actually rewrite this (fog)(x) as f(g(x)) --- i think this one is clearer. now let's substitute g(x) to f(x): (fog)(x) = f(g(x)) = 3x-5 = 3[g(x)] - 5 (fog)(x) = 3(2 - x^2) - 5 (fog)(x) = 6 - 3x...
*March 31, 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: if Q is (-), heat is released and if (+), heat is absorbed now we can only apply ...
*March 31, 2011*

**math**

recall that the area of a triabgle is given by A = (1/2)*bh where b = base h = height substituting, A = (1/2)(b)(12) A = 6b hope this helps~ :)
*March 31, 2011*

**Matt 116 Algebra**

what about y = 45x + 12 ? do you need to graph it ? or solve for x in terms of y ?
*March 31, 2011*

**math**

to solve this you divide 4.7 by 1, then multiply by 100: 4.7/1 * 100 4.7 * 100 = 470% hope this helps~ :)
*March 31, 2011*

**math**

4*3*2 = 24
*March 31, 2011*

**Algebra 1A**

i suppose this means that (17,8) is a point on the graph or a solution to the equation,, if so, it means we need to find for the slope, m. substituting the x- and y-coordinate to the equation: y = mx - 16 8 = m(16) - 16 8 + 16 = 16m 24 = 16m 24/16 = (16/16)m 3/2 = m rewriting ...
*March 31, 2011*

**math**

recall that the volume of a cylinder is given by V = pi*r^2*h where r = radius h = height substituting, V = pi*(8^2)*(7) V = 3.14*64*7 V = 1407.43 cubic km hope this helps~ :)
*March 30, 2011*

**math**

your answer is correct. :)
*March 30, 2011*

**english**

the verb is: resumed
*March 30, 2011*

**Algebra**

2a - b = ac + 3b to get a, first we need to transpose all terms containing a to one side of equation, and all other terms to the other side,, in this case the terms containing a are 2a and ac. let's just transpose them to the left side of equation,, since ac is on the ...
*March 30, 2011*

**math algebra**

do you mean something like this: [2(a^10)(b^2)][3(a^2)(b^2)] if so, then for constants, we just multiply them normally,, for the variables, recall some laws of exponent,, multiplying terms of same base is also equal to base raised to sum of its exponents,, for example 5^2 * 5^...
*March 30, 2011*

**math**

recall that area of square is A = s*s where s = length of a side of square therefore, substituting the given area: 36 = s*s 36 = s^2 get the squareroot 6 = s thus the length of side of square is 6 units. hope this helps~ :)
*March 30, 2011*

**algebra**

4xx - 36 can also be written as 4x^2 - 36 to factor this, notice that 4x^2 and 36 are both perfect squares (meaning they have an exact squareroot),, and 4x^2 - 36 is a difference of two squares. recall that if an expression is in the form (a^2 - b^2) it can also be written as...
*March 30, 2011*

**Math**

first recall that perimeter of a rectangle is P = 2(L+W) where L = length W = width substituting, 12 = 2(L+W) 6 = L+W now we need to find for positive, nonzero integers whose sum is 6,, the possible values are: L=5 and W=1 L=4 and W=2 L=3 and W=3 (this is a square but note ...
*March 29, 2011*

**math**

recall that the equation of a circle is given by (x-h)^2 + (y-k)^2 = r^2 where h = x-coordinate of the center k = y-coordinate of the center r = radius since in the problem, the center lies at (-8, -4) we have h = -8 k = -4 also, we need to solve for the radius from the ...
*March 29, 2011*

**geometry**

recall that the area of rhombus is just A = b*h where b = base and h = height we already have the base, which is 5 cm. we need to find for the height,, to get this, observe that if we draw the rhombus and draw a broken line representing the height, we see that a right triangle...
*March 29, 2011*

**Pre calc**

first we can transpose the - lnx to the right side of equation, 0.5 ln (x+3) = ln x recalling some laws of exponents, we can rewrite 0.5 ln (x+3) as ln (x+3)^0.5 therefore ln (x+3)^0.5 = ln x now we can equate the terms inside the ln: (x+3)^(1/2) = x square both sides: x+3 = x...
*March 29, 2011*

**Algebra**

note that we can rewrite the squareroot of a number by raising this number by 1/2 example, sqrt(5) = 5^(1/2) therefore in the problem we have sqrt(14abc) = (14abc)^(1/2) = [14^(1/2)][a^(1/2)][b^(1/2)][c^(1/2)] sqrt(2ab) = (2ab)^(1/2) = [2^(1/2)][a^1/2][b^1/2] now for the ...
*March 29, 2011*

**science**

recall that density is mass per unit volume, or d = m/V thus you need mass of the wooden block, and its volume,, to get mass you can use appropriate weighing scale and for the volume, you can measure its length, width and height since the volume of a rectangular solid (this is...
*March 29, 2011*

**math**

to find the slope of the line, we transform this given equation in the form, y = mx + b where m = slope and b = y-intercept thus for (1) 7x + 13y = 91, we first divide all term by numerical coefficient of y (which is 13) to get y alone: (7/13)x + (13/13)y = 91/13 (7/13)x + y...
*March 29, 2011*

**trig**

recall that cos x = sin (90-x) 90-x = 90-54 = 36 thus cos 54 = sin 36 hope this helps~ :)
*March 29, 2011*

**math**

to round a number to the nearest thousands: first find the digit in the thousands place, then look at the number to the right of the thousands place,, if this number is greater than or equal to 5, add 1 to thousands place; less than 5, thousands digit remains the same in the ...
*March 29, 2011*

**math**

253
*March 29, 2011*

**maths**

to get the solution/roots, we can use quadratic formula: x = [-b +- sqrt(b^2 - 4ac)]/(2a) where a = numerical coefficient of x^2 b = numerical coefficient of x c = the constant in the problem, x^2+5x-6 = 0, thus a = 1, b = 5, c = -6 substituting: x = [-b +- sqrt(b^2 - 4ac)]/(...
*March 29, 2011*

**maths**

discriminant is b^2 - 4*a*c where a = numerical coefficient of x^2 b = numerical coefficient of x c = the constant in the problem, 4x^2-x-3, thus a = 4, b = -1 and c = -3 substituting (-1)^2 - 4(4)(-3) 1 - (16)(-3) 1 + 48 49 hope this helps~ :)
*March 29, 2011*

**math**

let r = radius of cylinder when you draw a sphere that fits exactly inside a cylinder, you will observe that radius of cylinder = radius of sphere, and height of cylinder = diameter of sphere recall that surface area of sphere = 4*pi*r^2 and lateral surface area of cylinder = ...
*March 29, 2011*

**chemistry**

assuming the gas is ideal, we can use the formula: P1*V1 = P2*V2 where P1 = initial pressure V1 = initial volume P2 = final pressure V2 = final volume substituting: 735 * 100 = 700 * (V2) V2 = 105 mL hope this helps~ :)
*March 29, 2011*

**science**

assuming the Hydrogen gas is ideal, we can use the formula: (V1)/(T1) = (V2)/(T2) where V1 = initial volume T1 = initial temperature (units in Kelvin) V2 = final volume T2 = final temperature (units in Kelvin) since the given temp are in degree Celsius, we first convert it to ...
*March 29, 2011*

**chemistry**

assuming the gas is ideal, we can use the formula: P1*V1 = P2*V2 where P1 = initial pressure V1 = initial volume P2 = final pressure V2 = final volume substituting: (0.935)(1.44) = (P2)(0.275) P2 = 4.896 atm hope this helps~ :)
*March 29, 2011*

**chemistry**

assuming the gas is ideal, we can use the formula: (V1)/(T1) = (V2)/(T2) where V1 = initial volume T1 = initial temperature (units in Kelvin) V2 = final volume T2 = final temperature (units in Kelvin) since the given temp are in degree Celsius, we first convert it to Kelvin by...
*March 29, 2011*

**for the 2nd question**

let x = number according to the first statement, we multiply the number by three, then we add 7 to get 16,, writing in equation: 3x + 7 = 16 now solve for x,, first we transpose the 7 on the other side of equation,, to do this we change its sign from positive to negative: 3x...
*March 29, 2011*

**algebra 1**

first represent the unknowns using variables: let x = number of 24-cent stamps used let 2x = number of 39-cent stamps used (according to the second statement) since the total is 7.14 dollars, 0.24x + 0.39(2x) = 7.14 now we solve for x: 0.24x + 0.78x = 7.14 1.02x = 7.14 x = 7 (...
*March 29, 2011*

**30-60-90**

the opposite angle of the shorter leg is the smaller angle (which is the 30 degrees) since in a 30-60-90 triangle, the hypotenuse is twice the shortest side, and the longer leg is sqrt(3) times the shortest side: hypotenuse: 2*5.4 = 10.8 ft longer side: sqrt(3)*5.4 = 9.353 ft ...
*March 28, 2011*

**algebra 2**

since when this is drawn it forms a right triangle, we use pythagorean theorem: c^2 = a^2 + b^2 where c = hypotenuse a and b are base and height of the triangle therefore: c^2 = 14^2 + 21^2 c = sqrt (196 + 441) c = 25.24 ft hope this helps~ :)
*March 28, 2011*

**math**

since AF is the perpendicular bisector of BD, therefore BF=FD. since DF=FD=13, BF=13 now, if you draw this figure, you will see that you form a right triangle (AFD) when you connect A and D,, connecting A and B, you form another right triangle,, since they share a common ...
*March 28, 2011*

**math**

first convert 5 mm to cm recall that 10 mm = 1 cm thus 5 mm = 1/2 cm = 0.5 cm then we subtract the thickness by the outer diameter: 41 - 2*0.5 41 - 1 = 40 cm hope this helps~ :)
*March 25, 2011*

**math**

-35 / 5 = -7
*March 24, 2011*

**algerbra**

but i don't see any division operation,, it's only subtraction...
*March 24, 2011*

**Math**

note: 1 dozen = 12 cookies,, thus 3 dozen = 3*12 = 36 cookies let x = cups of sugar needed we use ratio and proportion: 20 : (1/4) = 36 : x we can rewrite this into fraction form: 20/(1/4) = 36/x we then cross multiply,, 20*x = (1/4)*36 20x = 9 x = 9/20 cups hope this helps~ :)
*March 24, 2011*

**Math**

to get the resultant or the total distance, we use distance formula: d = sqrt[ (x2-x1)^2 + (y2-y1)^2 ] where (x1,y1) is our reference/starting point, and (x2,y2) is the final point assuming our reference point is at the origin which is at (0,0) d = sqrt[ (x2)^2 + (y2)^2 ] ...
*March 23, 2011*

**stoichiometry**

first, make sure the equation is balanced,, to determine which is limiting, we calculate the amount of product produced by each given: for 6 mol N2: 6 mol N2 * (2 mol NH3 / 1 mol N2) = 12 mol NH3 for 12 mol H2: 12 mol H2 * (2 mol NH3 / 3 mol H2) = 8 mol NH3 (a) since H2 ...
*March 23, 2011*

**stoichiometry**

**i reposted this** first, make sure the equation is balanced,, to determine which is limiting, we calculate the amount of product produced by each given: for 6 mol N2: 6 mol N2 * (2 mol NH3 / 1 mol N2) = 12 mol NH3 for 12 mol H2: 12 mol H2 * (2 mol NH3 / 3 mol H2) = 8 mol NH3...
*March 23, 2011*

**Pre Calc**

oh yeah,, sorry about that. 0 is also a solution~ thanks for correcting me, sir~ :)
*March 23, 2011*

**Pre Calc**

recall that tan(x) can be rewritten as tan (x) = sin (x) / cos (x) substituting: sin(x) / cos(x) = 5 sin(x) the sin(x) will be cancelled: 1/cos(x) = 5 cos(x) = 1/5 solving this, x = +/- 1.369 since it must be on interval -π < x < π x = - 1.369
*March 23, 2011*

**math**

6n^2-19n+15=0 to solve this we can either factor it (if it's factorable) or use quadratic formula,, here we just use quadratic formula: for a given quadratic equation, ax^2 + bx + c = 0, x = [-b +- sqrt(b^2 - 4*a*c)]/(2*a) note: +- is plus or minus where a = numerical ...
*March 23, 2011*

**math**

to get the fractional part of girls, we first subtract 35 from 80 to get the number of girls: 80 - 35 = 45 then we divide this by the total, which is 80: 45/80 reduce to lowest term by dividing both numerator and denominator by the GCF (greatest common factor) which is 5: 45/5...
*March 23, 2011*

**geometry**

recall that the volume of rectangular prism is given by V = L*W*H where L=length, W=width, H=height substituting the given: V = 2*3*5 V = 30 cubic cm recall that the surface area of rectangular prism is given by SA = 2LH + 2WH + 2LW substituting the values: SA = 2*2*5 + 2*3*5...
*March 23, 2011*

**math**

by observation, we see that a given value of x is 2 greater than its corresponding value of y,, since it's fixed (or the difference between the values is constant), we say that the relationship between them is linear. getting the equation, we first find the slope of the ...
*March 23, 2011*

**math**

y = x - 4 to get y, just plug in each given value of x,, if x = 4, y = 4 - 4 = 0 if x = 0, y = 0 - 4 = -4 if x = -4, y = -4 - 4 = -8 if x = -6, y = -6 - 4 = -10 hope this helps~ :)
*March 23, 2011*

**chemistry**

to find the mass percentage of one component, you divide the its mass to the total mass * 100 for example, if you have initially 20 grams of Na and 30 grams of Fe, total mass = 20 + 30 = 50 if we want to find mass percentage of Na: (20/50) * 100 = 40% for mass percent of Fe: (...
*March 23, 2011*

**math**

your answer, 48<32, is correct (i mean, yes it's false),, hmm i don't see another statement which is false~
*March 23, 2011*

**Math**

6/8 = 3/4 since a circle has 360 degrees (central angle), we get 3/4 of 360: (3/4)*360 = 270 degrees hope this helps~ :)
*March 23, 2011*

**math**

let x = number of gallons the when tank is full according to first statement, initially the tank is 1/5 full. thus we can write it as (1/5)x according to second statement, he bought 6 gallons, thus we add 6 to the initial amount, and it becomes 7/10 full or (7/10)x rewriting ...
*March 23, 2011*

**science**

when you burn/ignite hydrogen in a test tube, it should produce a "popping" sound~ hope this helps~ :)
*March 23, 2011*

**maths**

the figure is a rectangular solid,, recall that the volume of a rectangular solid is given by: V = L*W*H where L=length , W=width , H=height substituting the values given: V = 5*4*6 V = ? now solve this using calculator,, units in cubic feet,, hope this helps~ :)
*March 23, 2011*

**math**

recall that the area of a circle is given by: Area = pi*r^2 since in the problem, diameter is given, we first get radius: diameter = 2*radius d/2 = r 15/2 = 7.5 ft = r thus A = pi*r^2 A = 3.14*7.5^2 A = ? now solve this using calculator,, to round off, first you need to know ...
*March 23, 2011*

**geometry**

..but we need to see the figure.
*March 10, 2011*

**Math- Algebra II**

8^(x-2) = (1/16) first, we can observe that both 8 and 16 are powers of 2, thus we express 8 and 1/16 as 2 raised to some power: 8 = 2*2*2 = 2^3 1/16 = 1/(2*2*2*2) = 1/(2^4) recall that when a certain number raised to an exponent is on the denominator, and we want it to be on ...
*March 9, 2011*

**math?**

to convert this to percent, first convert to decimal form,, you can use calculator to divide it: 9/54 = 0.1667 in percent, you just multiply it by 100: 0.1667*100 = 16.67% hope this helps~ :)
*March 9, 2011*

**math**

to get the greatest common factor, we first find the factors of each number (we call it a factor of a certain number if that certain number is divisible by the factor or it gives zero remainder when divided by the factor),, for example, 10 has factors 1, 2, 5 and 10, because ...
*March 9, 2011*

**no question**

..what's the question?
*March 9, 2011*

**alg 1**

there are several ways to solve this, but any quadratic equations, factorable or non-factorable, we use quadratic formula: for a quadratic equation in the form ax^2 + bx + c = 0, we can solve the roots using the quadratic formula: x = [-b +/- sqrt[b^2 - 4ac]] / (2a) where the ...
*March 9, 2011*

**prealgebra**

let x = width of rectangle let x+7 = length o rectangle (since according to first statement, length is 7 greater than the width represented by x) recall that perimeter of rectangle is: P = 2*L + 2*W substituting,, 54 = 2(x+7) + 2x 54 = 2x + 14 + 2x 54 = 4x + 14 54 - 14 = 4x 40...
*March 9, 2011*

**physics**

let x = support at left end let y = support at right end now, to get the reaction force at the left support, we sum moments at the right end, so that y will not be included in our calculation, and we can directly solve for x,, *recall that moment = (force)*(distance ...
*March 8, 2011*

**Math**

from the values, we can observe that the values of x are multiples of 8, and that if we multiply the values of y to 8, we get the values of x: 1*8 = 8 2*8 = 16 3*8 = 24 etc. now we can write an equation: y*8 = x or x - 8y = 0
*March 7, 2011*

**Math**

from the values, we can observe that the values of x are multiples of 8, and that if we multiply the values of y to 8, we get the values of x: 1*8 = 8 2*8 = 16 3*8 = 24 etc. now we can write an equation: y*8 = x or x - 8y = 0
*March 7, 2011*

**Math**

*i reposted this from the values, we can observe that the values of x are multiples of 8, and that if we multiply the values of y to 8, we get the values of x: 1*8 = 8 2*8 = 16 3*8 = 24 etc. now we can write an equation: y*8 = x or x - 8y = 0
*March 7, 2011*

**Geometry-8th grade**

it's correct~ :)
*March 7, 2011*

**math**

for the 1st question: it would be difficult to present here the solution for long division... but the answer should be 149.375 for the 2nd question: weight which can be carried by truck: 225 kg / truck thus, 4 trucks can carry all in all: 4*225 = 900 kg but the weight of all ...
*March 7, 2011*

**math**

but we don't see the figure...
*March 7, 2011*

**physics -- projectile motion **

oops, sorry the formula for range must be R = (vo)^2 * sin (2*theta) / g i just remembered that the 2g is for the max height: h,max = (vo)^2 * [sin (theta)]^2 / 2g but explanation and proving is still the same~ :)
*March 7, 2011*

**physics -- projectile motion **

recall that the formula for range is: R = (vo)^2 * sin (2*theta) / (2g) where vo = initial velocity theta = angle of release g = acceleration due to gravity (9.8 m/s^2) now, if we're given the initial velocity, the value of range will depend on theta,, observing this, if ...
*March 7, 2011*

**Pre-Algebra**

useful conversion: 1 meter = 100 centimeters first, we convert the given with units of centimeters into meters: 480 centimeters = ? meters to do this, we just divide 480 by 100 or: 480/100 = 4.80 meters 98/100 = 0.98 meters then we add these two to get the total length that he...
*March 7, 2011*

**Math**

let x = length of the first let 64 - x = length of the second since they are in ration 2:3, we can write this as: 2/3 = x/(64-x) cross-multiplying, we have: 2(64-x) = 3x 128 - 2x = 3x 128 = 5x x = 25.6 inches 64-x = 38.4 inches hope this helps~ :)
*March 7, 2011*

**Math: Logarithms**

recall that when the expression inside the log is raised to a certain power, we can write the exponent outside of the log, for instance: log (x^2) = 2 log x log [(2y)^0.5] = 0.5 log 2y thus for the problem, we can rewrite it as: (log(x^6) + 2log(y^3)) / log(xy) (6 log x + 6 ...
*March 7, 2011*

**math**

(1) x + 5y = -3 (2) 3x - 2y = 8 substitution method: we first choose one of the equation, and express one of the variables in terms of the other variable,, here let's choose equation (1), and express x in terms of y: x + 5y = -3 x = -3 - 5y now, we substitute this to ...
*March 7, 2011*

**math**

recall that the area of a triangle is A = bh/2 b = base and h = height substituting the values: 90 = b*12/2 90 = b*6 b = 15 meters hope this helps~ :)
*March 7, 2011*

**Geometry**

recall some formulas: Volume of Sphere = (4/3)*pi*(r^3) Surface Area of Sphere = 4*pi*(r^2) since we do not know the value of radius, we get it from the surface area: 804 = 4*pi*r^2 now solve for r with your calculator~ after solving r, plug in this value to the formula for ...
*March 7, 2011*

**math**

first, we convert the given in same units,, let's use ft as units,, since 12 inches = 1 foot, we convert the given dimensions for the tiles into ft: 12 inches = 1 ft 12 inches = 1 ft then we get the areas of both tiles and floor area to be installed by tiles: A,tile = 1*1...
*March 7, 2011*