Thursday

January 29, 2015

January 29, 2015

Total # Posts: 1,498

**math**

it's 20/(4/3),, first simplify this,,
*October 29, 2010*

**math**

recall that speed or rate is distance traveled over time, or: speed, v = d/t thus, you compare Anna's speed and Julia's speed: Anna: v = 20/(1 1/3) Julia: v = 246/(16) *note: first convert mixed number to improper fraction before dividing. hope this helps. :)
*October 29, 2010*

**College Algebra URGENT**

(fog)(x) is also f(g(x)) which means you substitute g(x) to the function of f(x),, (the x variables in f(x) will be g(x)), thus: (fog)(x) = 1/([g(x)]+4) (fog)(x) = 1/[(1/(6x+4) + 4] then simplify it.
*October 29, 2010*

**math correct or not correct**

Right. :)
*October 29, 2010*

**math correct or not correct**

right~! :)
*October 29, 2010*

**chemistry **

simplified energy balance: Q,absorbed + Q,lost = 0 , or Q,absorbed = -Q,lost where Q = m*c(Tf - Ti) in which Q=heat in J, m=mass in kg, c=specific heat capacity (which has a definite value for various substances) in J/(kg*C), T=temperature in Kelvin *Tf=final temp (the same ...
*October 29, 2010*

**math **

Right~! :) qt/day is fine. no need to write 1.
*October 29, 2010*

**math **

since 1440 is a whole number, you can rewrite it as 1440 = 1440/1 *any whole number divided by 1 is itself. then multiply fractions like normal multiplication,, numerator: number above the line, denominator: number below the line, numerator times numerator, and denominator ...
*October 29, 2010*

**math **

right, 24*60 = 1440 then 1440 * 5/8 = ?
*October 29, 2010*

**math **

recall these conversions: 1 qt = 32 fl oz 1 day = 24 hours = 24*60 minutes using dimensional analysis to cancel units: (20 oz)*(1 qt/32 oz) = 20/32 = 5/8 qt (1/1 min)*(24*60 min/1 day) = 24*60/day now multiply them (units in qt/day): (5/8)*(24*60) how do you multiply fractions...
*October 29, 2010*

**Math **

True. it's actually a theorem.
*October 29, 2010*

**Calculus**

is that ln (x^2) or (ln x)^2 ? anyway, in any case, it is not differentiable at x = 0 because if you get the derivative, for ln (x^2): ln (x^2) = 2*ln x derivative of 2*ln x = 2/x for (ln x)^2: derivative (ln x)^2 = 2*(ln x)/x if you substitute x=0 to the derivative, the ...
*October 29, 2010*

**physics**

acceleration is change in velocity over time, or: a = (v - v0)/t where v = final velocity in m/s v0 = initial velocity in m/s t = time in s assuming that it is initially at rest, v0 = 0,, the final velocity, v, is the speed of light, which is approximately 3.0 x 10^8 m/s ...
*October 29, 2010*

**physics**

first, recall formula for Force: F = ma where m = mass in kg, and a = acceleration in m/(s^2) then also recall the formula for acceleration,, acceleration is change in velocity over time, thus: a = (v - v0)/t where v = final velocity in m/s v0 = initial velocity in m/s t = ...
*October 28, 2010*

**physics**

acceleration is change in velocity over time, or: a = (v - v0)/t where v = final velocity in m/s v0 = initial velocity in m/s t = time in s assuming that it is initially at rest, v0 = 0,, the final velocity, v, is the speed of light, which is approximately 3.0 x 10^8 m/s ...
*October 28, 2010*

**physics**

first, recall formula for Force: F = ma where m = mass in kg, and a = acceleration in m/(s^2) then also recall the formula for acceleration,, acceleration is change in velocity over time, thus: a = (v - v0)/t where v = final velocity in m/s v0 = initial velocity in m/s t = ...
*October 28, 2010*

**math **

where is a and b? and is the "t" in the equations plus or another variable?
*October 28, 2010*

**algebra**

you're welcome, Jordyn! :)
*October 28, 2010*

**algebra**

(36x^2 - 49y^2)/(6x + 7y) notice that the numerator is a difference of two squares,, recall: a^2 - b^2 = (a+b)(a-b) thus the numerator can be factored into: (6x+7y)(6x-7y)/(6x+7y) then cancel the common factor and you get 6x - 7y hope this helps.
*October 28, 2010*

**math**

recall these conversions: 1 qt = 32 fl oz 1 day = 24 hours = 24*60 minutes using dimensional analysis to cancel units: (20 oz)*(1 qt/32 oz) = 20/32 = 5/8 qt (1/1 min)*(24*60 min/1 day) = 24*60/day now multiply them (units in qt/day): (5/8)*(24*60) = ? hope this helps.
*October 28, 2010*

**math**

no,, check again your multiplication.
*October 28, 2010*

**math**

recall these conversions: 1 qt = 32 fl oz 1 day = 24 hours = 24*60 minutes using dimensional analysis to cancel units: (20 oz)*(1 qt/32 oz) = 20/32 = 5/8 qt (1/1 min)*(24*60 min/1 day) = 24*60/day now multiply them (units in qt/day): (5/8)*(24*60) = ? hope this helps.
*October 28, 2010*

**math**

recall these conversions: 1 qt = 32 fl oz 1 day = 24 hours = 24*60 minutes using dimensional analysis to cancel units: (20 oz)*(1 qt/32 oz) = 20/32 = 5/8 qt (1/1 min)*(24*60 min/1 day) = 24*60/day now multiply them (units in qt/day): (5/8)*(24*60) = ? hope this helps.
*October 28, 2010*

**Calculus**

is that the derivative? if it is, ln(1/x) can be written as: ln (x^-1) = -ln(x) since the derivative of ln (x) is 1/x, then derivative of -ln(x) = ln(1/x)= -1/x hope this helps.
*October 28, 2010*

**Find the limit**

first, we observe what happens when t approaches 5: lim (t+2)/(t-5) as t->5 7/0 = infinity which can be (+) or (-) infinity since it's 5- or to the left of 5, some of the values can be 4.99, 4.999, 4.9999,, if we choose for instance, 4.999, 4.999 - 5 = -0.001 *negative...
*October 28, 2010*

**chemistry**

punctuation? ...or do you mean units? molar mass can be in g/mol or lb/lbmol... they can be found in periodic table of elements.
*October 28, 2010*

**maths **

alright then. if using L'hopital's Rule is not allowed, then recall the property: lim (sin x)/x = 1 as x->0 therefore, lim [sin(x-1)]/(x^2 + x - 2) we can factor the denominator: (x^2 + x - 2) = (x-1)(x+2) we can then re-write the limit as: lim [sin(x-1)]/[(x-1)(x+2...
*October 28, 2010*

**maths **

is the function, like this: [sin(x-1)]/(x^2 + x - 2) or this: sin [(x-1)/(x^2 + x - 2)] ?
*October 28, 2010*

**chem/math**

take the ln of both sides: ln [4.58*10^-15] = ln [e^(Ea/2537.02)] *since ln has a base of e, the term at the right side becomes: ln [4.58*10^-15] = (Ea/2537.02) now you solve for Ea. :)
*October 28, 2010*

**exponents math**

exponents means to multiply by itself,, thus: (A) (-1)^3 = (-1)(-1)(-1) = ? *solve for this. (B) here, only 1 is raised by 3,, the negative sign (or the -1) is excluded: -(1)^3 = -(1)(1)(1) = ? (C) process is same as that of letter (A) (D) process is same as that of letter (B...
*October 28, 2010*

**math**

first look for the least common denominator (LCD) of the denominators (4, 3 and 6) LCD = 12 now multiply this 12 to all terms to have whole numbers and coefficients: 12*(x/4 + 2x/3 + x/6) = 12*(1/2) 3x + 8x + 2x = 6 13x = 6 solve for x by dividing 6 by 13.
*October 28, 2010*

**science**

is 5.20x10^-3 in moles? combustion of methane (CH4): CH4 + O2 --> H2O + CO2 *combustion reaction: products are usually water and carbon dioxide balance this equation first, then use stoichiometric ratios (the ratio of the moles of CH4 and CO2), to find number of moles of ...
*October 28, 2010*

**maths **

i interpreted this in two ways: first, lim [sin(x-1)]/(x^2 + x - 2) as x->1 *since, there is no common factor between numerator and denominator, it's in simplest form,, also you substitute 1 to both [sin(x-1)] and (x^2 + x - 2): sin(x-1) = sin (1-1) = 0 (x^2 + x - 2) = ...
*October 28, 2010*

**Math**

first, represent unknowns with variables: let x = number of hours she worked for monday-friday let y = number of hours she worked for saturday set up equation according to conditions given: (1) x + y = 42 (2) 6x + 9y = 273 there are many ways to solve for this,, if we use ...
*October 28, 2010*

**Math**

represent unknowns using variables: let x = length of a side of equilateral triangle let x+10 = length of a side of square *recall that perimeter of any polygon is the sum of the lengths of its sides,, since square has 4 sides with equal lengths, and equilateral triangle has 3...
*October 28, 2010*

**algebra**

first, represent unknowns using variables: let x = price of hamburger let y = price of hotdogs set up equation: (1) 6x + 3y = 27 (2) 5x + y = 18.75 there are several ways to solve this,, but id we use substitution method,, choose an equation (in this case, equation (2)),, then...
*October 28, 2010*

**Calculus**

y' = (-1)/{[(x-3)^(3/2)][(x-1)^(1/2)]}
*October 28, 2010*

**math**

if 8 marbles are blue then 28 - 8 = 20 are green and red marbles then if we let x = the number of green marbles, then the number of red marbles is 3 times the number of green marbles, or 3*x,, and their total sum must be 20: x + 3*x = 20 combining similar terms, 4x = 20 now ...
*October 28, 2010*

**math**

first, represent the unknowns with variables: let x = number of shamrocks let y = number of horseshoes then set up equations according to the conditions given: (1) y/x = 11/2 (2) 5x = y - 3 there are several ways to solve this,, if we choose to solve it by substitution method...
*October 28, 2010*

**college-typo**

oops, some typo: x = [-1 + i*sqrt(11)]/6 ; and x = [-1 - i*sqrt(11)]/6
*October 28, 2010*

**college**

since it's not factorable, we use quadratic formula: x = [-b +- sqrt(b^2 -4ac)]/(2a) where a=3, b=1, and c=1 substituting: x = [-1 +- sqrt(1^2 - 4*3*1)]/(2*3) x = [-1 +- sqrt(-11)]/6 thus x = [-1 + i*sqrt(11)]/6 ; and x = [-1 - i*sqrt(-11)]/6 *note: i = sqrt(-1) hope this ...
*October 28, 2010*

**calc**

**i'll just retype it to make the integration part clearer: integral 2x = [2x^(1+1)]/(1+1) = (2x^2)/2 = x^2 integral x^2 = [x^(2+1)]/(2+1) = (x^3)/3
*October 28, 2010*

**calc**

is y = 2x - x^2 the function given? if it is, area under the curve means the integral at these particular bounds,, first you have to recall how to integrate: for ax^n (a is constant), add 1 to the power, then this n+1 must be divided: integral (ax^n) = (a)[x^(n+1)]/(n+1) thus ...
*October 28, 2010*

**physics**

the formula for vertical distance is, d = (v0)*t-(1/2)g*t^2 where v0=initial velocity, t=time, and g=acceleration due to gravity, which is approximately 9.8 m/(s^2) *now since this is freefall, v0 = 0 and the formula reduces to: d = -(1/2)g*t^2 d = -(1/2)*9.8*(2.5^2) then ...
*October 28, 2010*

**math**

white: 3 9 27 black: 1 4 13 notice that for the white triangle,, let n = number of terms,, if n=1 , white=3, if n=2, white=9, thus the pattern for white is white = 3^n for the black, notice that the next term would be the sum of previous values of both white and black,, for ...
*October 28, 2010*

**math**

V,sphere = (4/3)*pi*r^3 V,sphere = (4/3)*3.14*5^3 then solve for V. (units in inch^3)
*October 28, 2010*

**Math **

first solve for y,, to do this, transpose all terms without variable 'y' into the other side of equation: 35 - 5y = 0 -5y = -35 *when transposing a term, the sign becomes the opposite (thus 35 becomes -35) then divide everything by -5 to get y alone: (-5/-5)y = (-35/-5...
*October 28, 2010*

**Math - horizontal asymptote of f(x) (check)**

horizontal asymptote: y = 0 , as x approaches plus/minus infinity
*October 28, 2010*

**Math - horizontal asymptote of f(x) (check)**

oops i got it wrong horizontal asymptote occurs where the value of y is restricted,, so in the given function f(x)= y = x/(x-1)^2, what value of y is restricted?
*October 28, 2010*

**Math - horizontal asymptote of f(x) (check)**

horizontal asymptote occurs where the value of x is restricted,, n the given function f(x)=x/(x-1)^2, what value of x is restricted?
*October 28, 2010*

**5th math**

i'm very sorry, mr. Writeacher! i didn't know that, because i'm also a student. i promise not to do it again.
*October 28, 2010*

**5th math**

you just have to measure the lengths of the sides of the triangle you want to draw. for instance, if isosceles, choose the length of the two sides which must be equal (any length, like 3 cm or 5 cm) using your ruler, then the length of the last side must be different from the ...
*October 28, 2010*

**science**

first recall the density of water,, density is mass per unit volume,, the density of water is approximately 1 g/mL , therefore: d = m/V where m = mass in g, and V = volume in mL 1 = m/16 m = 16 grams so there,, :)
*October 28, 2010*

**Physics**

you need to first look for the latent heat of fusion (Lf) --- this is a constant, then use the formula: Q = m(Lf) where Q = heat in Joules, m = mass in grams *since it melted, it definitely absorbed/gained heat, thus Q is (+) so there,, :)
*October 28, 2010*

**5th grade math**

isosceles and equilateral triangles are different because, isosceles --> only two sides are of equal length, equilateral --> all three sides are equal isosceles and equilateral triangles both have three sides. (one characteristic they both have) so there,, :)
*October 28, 2010*

**5th math**

no, that's an octagon. a regular polygon has sides with equal lengths, and also with equal angles. :)
*October 28, 2010*

**Calculus 1**

first, recall chain rule, since there there is a function of x multiplied by another function of x (that is, x^7 and h(x)),, given a function f(x)=g(x)*h(x) f'(x) = g'(x)*h(x) + g(x)*h'(x) therefore, to get derivative of f(x)=x^7 *h(x), first get the derivative of ...
*October 28, 2010*

**Math. **

you have to divide 420 by 2 1/4,, to do this, you must first convert 2 1/4 into improper fraction: 2 1/4 = 9/4 *note that to convert mixed number into improper fraction, multiply the denominator (which is 4) by the whole number (which is 2), then add the numerator (which is 1...
*October 28, 2010*

**math**

hmm, is this what you mean: since output is half of the input, output = input / 2
*October 28, 2010*

**math(Pre-Calculus)**

-f(x) means you just have to multiply every term by -1, like for (A) -(3x-1) = -3x + 1 try it to letter (B). :) then substitute the answers you get into the F(x).
*October 28, 2010*

**math(Pre-Calculus)**

is that really F(x)= (x+h)-f(x) or F(x)= f(x+h)-f(x) ? *the f(x+h)* anyway, A.) that's right. f(x+h) = 3(x+h)- 1 B.) you forgot to raise 2(x+h).. by 2.
*October 28, 2010*

**5th grade math**

please repost your question,, something that we can understand. or just describe the figure.
*October 28, 2010*

**algebra 1**

first represent unknowns with variables: let x = length of the second carpet let x+30 = length of first carpet. since Area=length*width, and they have the same area, Area = 9*(x+30) = 15*x 9(x+30) = 15x now solve for x. then substitute this to x+30 to get length of first ...
*October 28, 2010*

**math**

right~ :)
*October 28, 2010*

**math**

you just have to divide,, but first convert 1 3/20 to improper fraction,, let me see your work first. :)
*October 28, 2010*

**math**

what do you mean rule? do you have to write an equation or something?
*October 28, 2010*

**math**

notice that the output is half of the input. :)
*October 27, 2010*

**6th grade**

to get variable 'm' alone, transpose all terms not containing m to the right side of equation,, but remember to reverse the sign: 5/8 + m = 1 m = 1 - 5/8 *note that the sign of 5/8 becomes negative* then to subtract fractions, you need to convert 1 to a fraction such ...
*October 27, 2010*

**math**

yes! that's right~! :)
*October 27, 2010*

**math**

first combine similar terms,, that is, add the numerical coefficient of x (or the number before x): -3/4 + 1/4 *since they have the same denominator, you can add the numerator directly: (-3+1)/4 = -2/4 it now becomes: (-2/4)x = -6 now, we can multiply -1 to both sides to ...
*October 27, 2010*

**6th grade math**

you have to divide,, for the first one, 1 divided by i/6 1 / (1/6) when you have to divide by a fraction, get first its reciprocal, that is interchange the numerator and denominator: 1/6 --> reciprocal is 6/1 then the operation now becomes multiplication: 1 / (1/6) becomes ...
*October 27, 2010*

**5 th grade math**

rounding off? to do this, first you have to know the places of each digit, for instance: 5,608 5 is thousands place 6 is hundreds place 0 is tens place, and 8 is ones place since in the question, round to nearest ten (which is 0), you look at the digit at the right (that is ...
*October 27, 2010*

**5 th grade math**

*half of 6 is 3 (hundred thousands place) *smallest odd digit is 1 (thousands place) how many digits? is it up to million? if yes, it's: 1 , 3 1 1 , 1 1 6 . 4 1
*October 27, 2010*

**math**

yes! that's right! :)
*October 27, 2010*

**math**

33/5 is right,, 12/4 is not. check it again,,
*October 27, 2010*

**math**

is that minus sign or equal sign? if equal sign, no it's not 5/11. alright,, convert first 2 3/4 into improper fraction,, let me see your work. :)
*October 27, 2010*

**math/algebra**

no. don't look for points yet. first, convert the given equation into slope-intercept form, y=mx+b,, alright i'll help you in this one: 3x+4y<12 now to solve for y, transpose 3x to the right side of equation, but the sign becomes the opposite (positive 3x becomes -...
*October 27, 2010*

**math/algebra**

oh, so it's "less than or equal to" you have to change this into y = mx + b (slope-intercept form), alright to do this, transpose 3x to the right side of equation, and divide everything by 4 to get y,, let me see your answer for this first. :)
*October 27, 2010*

**Math 8th grade algerbra**

yes,, (V,new)/V = 27,, and ration of dimensions is 3 (because it is tripled according to problem) now, how is 27 related to 3?
*October 27, 2010*

**Math 8th grade algerbra**

Volume of cylinder = area of the base * height , or V = pi*(r^2)*h V,original = pi*(3^2)(10) *you solve for this. then for the new one, r,new = 3*3 = 9 h,new = 3*10 = 30 V, new = pi*(9^2)(30) you solve also for this. then compare their volumes, find: (V,new)/V so there,, hope ...
*October 27, 2010*

**math **

for #1, it's correct but the sign must be positive. :) for #2, it's not 5/11. please check your solution again.
*October 27, 2010*

**math/algebra**

you don't actually have to convert it to decimal. improper fraction or mixed number is fine, unless it is stated in the problem that you have to convert it. :)
*October 27, 2010*

**math/algebra**

right~! :) now, you can cancel out 2 from both since it is a common factor: -10/6 = -(2 * 5)/(2 * 3) = -5/3 so there,, :)
*October 27, 2010*

**math/algebra**

set 1: 2 and 5 set 2: 2 and 3 what number is common from both set?
*October 27, 2010*

**math/algebra**

yes! that's right! :) now, from the factors of 10 (which is 2 and 5) and factors of 6 (which is 2 and 3), what number is common?
*October 27, 2010*

**math/algebra**

right. 5 and 2 are the factors of 10 because 2 * 5 = 10 now, what are the factors of 6?
*October 27, 2010*

**math/algebra**

5 and..? what do you multiply by 5 to get 10?
*October 27, 2010*

**math/algebra**

hmm,, well try this one, what are the factors of 10?
*October 27, 2010*

**math/algebra**

look for a common factor of 10 and 6,, for example if you have 6/4, 6 and 4 have a common factor of 2, thus you can factor out 2 from both: 2*3 / 2*2 = 3/2 like that. try it to -10/6 ~ :)
*October 27, 2010*

**math/algebra**

then reduce -10/6 to lowest term.
*October 27, 2010*

**math **

for #1, it's correct but the sign must be positive. :) for #2, it's not 5/11. please check your solution again.
*October 27, 2010*

**math**

what do you need to do? do you have to graph -0.2x<-12 in a number line?
*October 27, 2010*

**math/algebra**

no,, they have INFINITE solutions,, any point that will satisfy either equations is a solution,, :)
*October 27, 2010*

**math/algebra**

oh sorry. what did you not understand? these two equations are coinciding,, thus, any point that satisfies the equation is a solution,, coinciding means, they overlap, they are the same,, here, try to look at the second equation: 6x+8y=10 if you simplify this by dividing every...
*October 27, 2010*

**math/algebra**

oh alright then. (1) 3x + 4y = 5 (2) 6x + 8y = 10 if you want to cancel out x, you need to multiply -2 to equation (1) so that if added to 6x it becomes zero: -2(3x+4y=5) becomes -6x - 8y = -10 then add this to equation (2): -6x - 8y = -10 6x + 8y = 10 oh, it turned out both x...
*October 27, 2010*

**math/algebra**

(1) 3x+4y=5 (2) 6x+8y=10 to solve using elimination, you have to multiply a factor into the equation so that when you add/combine them, one of the variables gets eliminated or canceled out,, here, if you want to cancel out x, what do you need to multiply to equation (1) so ...
*October 27, 2010*

**Ap calculus**

is that at a=0 or x=0,, anyway, to get the derivative, do the chain rule since two different terms with x are multiplied,, to do this let g(x)=3x and h(x)=sin x thus d/dx [g(x)h(x)] = g(x)*h'(x) + g'(x)h(x) *g(x)*h'(x) = you get derivative of h(x)=sin x an multiply...
*October 27, 2010*

**SOLVE THE INEQUALITY **

to graph this, first convert this equation to slope-intercept form (y = mx + b),, then graph it like a normal line (imagine the inequality sign to be equal sign),, since the sign is only "greater than" (>) or "less than" (<) (not greater than or equal...
*October 27, 2010*

**SOLVE THE INEQUALITY **

solve for x or y? or, do you need to graph it?
*October 27, 2010*

**geometry**

circumference? oh you approximate pi to 22/7 and diameter is 3.5 ? therefore, you change 3.5 into mixed number, then into improper fraction, and multiply it to 22/7. so there,, :)
*October 27, 2010*

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