Sunday

March 29, 2015

March 29, 2015

Total # Posts: 29,295

**Calculus**

Use implicit differentiation x^2 + y^2 = 2xy 2x + 2y dy/dx = 2x dy/dx + 2y 2y dy/dx - 2x dy/dx = 2y - 2x dy/dx(2y - 2x) = 2y-2x dy/dx = (2y - 2x)/(2y - 2x) = 1 well, that was weird let's see why .... x^2+y^2=2xy x^2 - 2xy + y^2 = 0 (x - y)^2 = 0 x - y = 0 y = x ahhhh!, ...
*November 30, 2014*

**Sixth Grade Math**

good job
*November 30, 2014*

**Math PLEASE HELP ME**

invested at 12% ---- x invested at 8% ----- 2x invested at 10% -----210000- x - 2x = 210000-3x .12x + .08(2x) + .10(210000-3x) = 20100 times 100 12x + 16x + 10(210000-3x) = 2010000 -2x = -90000 x = 45000 so 45000 at 12% ---> 5400 90000 at 8% -------> 7200 75000 at 10...
*November 30, 2014*

**Geometry**

I painted the courthouse blue, but now my screen is all smudgy. How do I get the paint off my monitor?
*November 30, 2014*

**algebra**

1. I got 180.8 which would round to 181 2. yup 3. 172.3356 4. 87.5 Were you rounding off before you got to the last answers?
*November 30, 2014*

**Algebra word problem**

Robert's current age --- x Mary's current age ---- x+2 x + x+2 = 28 take it from there
*November 30, 2014*

**AP Calculus**

huh? they don't come any easier f(x) = -x^2 + x f ' (x) = -2x + 1
*November 30, 2014*

**Calculus**

Step 1 of any limit question for me is to sub in the approach value. I that turns out to be a real number, that is your answer, all done! so when x = -1 your expression = (1-2+3)/(1+1) = 2/2 = 1 looks like B to me
*November 30, 2014*

**Calc**

L(x) = f(a) + f ' (a) (x-a) , where x = a f(x) = cosx - sin 2x f ' (x) = -sinx - 2cos 2x L(x) = f(0) + f ' (0) (x-0) = 1-0 + (0-2)(x-0) = 1 - 2x
*November 30, 2014*

**AP Calculus**

f(x)=(x^2-3x)/x^2 you could use the quotient rule, but .... f(x)=(x^2-3x)/x^2 = 1 - 3/x = 1 - 3x^-1 f'(x) = 3x^-2 = 3/x^2
*November 30, 2014*

**Algebra**

(7.8*10 to the 12th power)*800 = 7.8*800* 10^12 = 62400 * 10^12 = 6.24 * 10^15 (7.8*10 to the 10th power)*80,000 = 624000 * 10^10 = 6.24 * 10^14 so what do you think ?
*November 30, 2014*

**SIXTH GRADE MATH**

correct Did you notice that your thinking was along the same lines as that in your previous problem?
*November 30, 2014*

**SIXTH GRADE MATH**

yes, you are correct (they signed up 6 volunteers in 3 weeks, so in 1 week they would sign up 1/3 of 6 , which is 2)
*November 30, 2014*

**SIXTH GRADE MATH**

You are welcome
*November 30, 2014*

**SIXTH GRADE MATH**

Your ratio is 2:3, which means that the total number of games must be a multiple of 5 the only number I see to fit that is 25 e.g. we can split 25 into 2 parts 10:15 = 2:3 but we could not do that with 26 games and still have whole numbers
*November 30, 2014*

**math**

17.4 L + 376 ml = 17.4 L + .376 L = 17.776 L (compare the simplicity of the metric system to the complication of the Imperial system in the 2 previous posts)
*November 29, 2014*

**Math**

let (5x^3 - x^2 + 20x - 8)/(x^2+4)^2 = (Ax + B)/(x^2 + 4) + C/(x^2+4)^2 or = ( (Ax+b)(x^2+4) + C )/(x^2=4)^2 = ( Ax^3 + 4Ax + Bx^2 + 4B+C)/(x^2+4)^2 matching up coefficients of the original numerator ... A = 5 B = -1 4A = 20 ---> confirms A=5 4B+C = -8 -4+C = -8 C = -4 so ...
*November 28, 2014*

**Math**

s^3 = 50653 s = 37 surface area = 6s^2 = 8214
*November 28, 2014*

**math**

3√7 is the best you can do
*November 28, 2014*

**maths**

area = x(x+12.8) , where x is the width more data needed to continue
*November 28, 2014*

**MATH**

√63 = √9 √7 = 3√7
*November 28, 2014*

**math**

i = .07/4 = .0175 n = 7(4) = 28 x(1.0175)^28 = 30000 x = 30000/1.0175^28 = $ 18456.85
*November 28, 2014*

**Math**

#2 , (without expanding) y - 1.5 = a(x+2)^2 a = (y-1)/(x+2)^2 to get x: (y-1.5)/a = (x+2)^2 x+2 = ± √( (y-1/5)/a ) x = -2 ± √( (y-1/5)/a ) follow the same steps for #1, which is easier
*November 28, 2014*

**math**

I think you have a typo Your statement is only true for n = 1 http://www.wolframalpha.com/input/?i=evaluate+3n+%2B+7n+-+2+for+n+%3D+1%2C2%2C3%2C4 Is there supposed to be a power somewhere?
*November 28, 2014*

**calculus**

a = -9.8 then v = -9.8t + c when t = 0 , v = 5 m/s 5 = 0 + c, ----> c = 5 v = -9.8t + 5 s = -4.9t^2 + 5t + k when t = 0, s =442 442 = 0 + 0 + k s = -4.8t^2 + 5t + 442 b) highest point when v = 0 0 = -9.8t + 5 t = 5/9.8 = appr .51 sec when t = .51 s = -4.9(.51)^2 + 5(.51) + ...
*November 28, 2014*

**maths**

Since the distance covered by the belt depends on the circumference of the circles , ... 150(2π(15)) = 300(2πr) 15π = 2πr r = 15/2 = 7.5 cm or the speed of the pulleys is inversely proportional to the their radii r/15 = 300/150 r/15 = 2 2r = 15 r = 7.5
*November 28, 2014*

**Algebra**

I assume you want her pay to be a function of the number of hourse worked let the number of hours worked be h Pay ≥ 10h + 7.5h pay ≥ 17.5 h
*November 28, 2014*

**Math**

I did a similar question last night just change the numbers http://www.jiskha.com/display.cgi?id=1417144323
*November 28, 2014*

**math**

number correct ---- x number incorrect ---- 200 - x number left unanswered--- 0 2x - (1/2)(200 - x) = 360 4x - 200 + x = 720 5x = 920 x = 184 so on his test he got 184 correct and 16 wrong. check: 184(2) - 16(1/2) = 368 - 8 = 360 with the new scoring system: score = 184/2 - 2(...
*November 28, 2014*

**MATH 100**

let the light be situated x ft from one light and 9-x from the other. Let the power be P, where P is a constant let I be the total illumination. I = P/x^2 + 10P/(9-x)^2 = Px^-2 + 10P(9-x)^-2 dI/dx = -2Px^-3 - 10P(9-x)^-3 (-1) = 0 for a min of I 10P/(9-x)^3 = P/x^2 divide by P...
*November 27, 2014*

**math**

happens to everybody
*November 27, 2014*

**math**

let the original fraction be x/y (x+1)/(y+1) = 2/3 3x + 3 = 2y + 2 ----> 3x - 2y = -1 , #1 (x-2)/(y-2) = 3/5 5x - 10 = 3y - 6 ----> 5x - 3y = 4 , #2 #1 times 3 ---> 9x - 6y = -3 #2 times 2 ---> 10x - 6y = 8 subtract them: x = 11 in #1: 33 - 2y = -1 -2y = -34 y = 17...
*November 27, 2014*

**math**

number of 20 paisa coins --- x number of 25 paisa coins --- 50-x 20x + 25(50-x) = 1150 20x + 1250 - 25x = 1150 -5x = -100 x = 20 so she has 20 of the 20paisa and 30 of the 25 paisa coins check: 20+30 = 50 , check! 20(20) + 25(30) = 1150 , check!
*November 27, 2014*

**Algebra**

n+d = 45 5n + 10d = 360 or n + 2d = 72 so... n+d = 45 n + 2d = 72 subtract them to eliminate the n , then solve for d sub d back into the first and all is easy.
*November 27, 2014*

**Algebra**

N + D = 45 5N + 10D = 360 ---> N + 2D = 72 Subtract them ---> D = 27 then in your head from the first equation, N = 18 So he has 27 dimes and 18 nickels check: 27+18 = 45 , check! 27 dimes = $2.70 18 nickels = $0.90 total = $3.60 check!
*November 26, 2014*

**math**

1/2 % = .5 % = .005 so you are correct. (your mom's 50% would be .5 )
*November 26, 2014*

**CaLC AB**

#2 tan(x+y) = x then sec^2 (x+y) * (1+dy/dx) = 1 sec^2 (x+y) + dy/dx sec^2 (x+y) = 1 dy/dx = (1 - sec^2 (x+y) )/(sec^2 (x+y) ) or = 1/sec^2 (x+y) - sec^2 (x+y)/sec^2 (x+y) = cos^2 (x+y) - 1 looks like e) is it.
*November 26, 2014*

**CaLC AB**

f(x) = sin^2 x or (sinx)^2 f ' (x) = 2sinxcosx or sin (2x) g ' (x) = x so is sin (2x) > x for x = 0, no x = 1.2 , sin(2.4) = .67.. , so no x = .9 , sin (1.8) = .97.. which is > .9 , so YES x = .8 , sin(1.6) = .99957.. which is > .8 , so YES x = 1.3 , sin 3 = ....
*November 26, 2014*

**AP CALC. AB**

f(x) = x^2 + 4x - 8 dy/dx = 2x+4 at x=2 , dy/dx = 8 f(2) = 4 + 8-8 = 4 tangent equation at x = 2 y-4 = 8(x-2) y-4 = 8x-16 y = 8x -12 8x-12 = 2(x^2 + 4x-8) 8x - 12 = 2x^2 + 8x - 16 2x^2 = 4 x^2 = 2 x = ± √2 so what do you think?
*November 26, 2014*

**Math**

so the TV was originally selling for 2999.99 ($3,000) the markdown was 1500 so the markdown was 1500/3000 = 1/2 or 50%
*November 26, 2014*

**geometry**

Go with MathMate, I misread the question
*November 26, 2014*

**geometry**

All angles in the equilateral triangle are 60° In the isosceles triangle the two base angles are 73 ° each ......... ( (180-34)/2 ) so angle ABD = 60+73 or 133°
*November 26, 2014*

**Trig**

1. can't see your diagram but will assume that the angle of 35° is between the two given sides, so ... R^2 = 98^2 + 55^2 - 2(55)(98)cos 145° 2. "each" vector ? , what vector 3. a = <9,8> b = <-8,7) a dot b = |a| |b| cosØ -72 + 56 = √...
*November 26, 2014*

**analytic**

duplicate post, see your other post
*November 26, 2014*

**analytic**

slope of first line = m1 = (6-9)/(2-1) = -3 slope m2 = (5-3)/(3+1) = 1/2 if Ø is the angle between them: tanØ = (m2-m1)/(1 + m2m1) = (1/2 - 3)/(1 + (1/2)(-3)) = (-5/2) / (-1/2) = 5 Ø = 78.7° to the nearest tenth
*November 26, 2014*

**Statistics**

z score = (your data value - mean)/sd I will do the first and fourth, follow the same procedure for the others 68, ? z = (68-70)/8 = -2/8 = -.25 ? 1.8 1.8 = (x - 70)/8 multiply by 8 14.4 = x-70 add 70 84.4 = x notice the z value may be ± but your data value must be ...
*November 26, 2014*

**Math**

10/12 = 50/60 = 25/30 = ... just multiply the numerator and denominator by the same non-zero constant e.g (5/6)*(2/2) = 10/12 etc
*November 26, 2014*

**Trig**

2csc^2x-8=0 csc^2 x = 4/2 = 4 then sin^2 x = 1/4 sinx = ±1/2 ---> so x can be in any of the 4 quads we know sinπ/6 = 1/2 so x = π/6 x = π - π/6 = 5π/6 x = π + π/6 = 7π/6 x = 2π - π/6 = 11π/6
*November 25, 2014*

**Trigonometry**

sin^2 x = 3/4 sinx = ±√3/2 I know sin 60° = √3/2 or sin π/3 = √3/2 so x = π/3, 2π/3 , 4π/4 , 5π/3 2 tan^2 x = √12 = 2√3 tan^2 x = √3 now you should know the trig ratios of the 30-60-90 triangle. once you ...
*November 25, 2014*

**Brief Calculus**

look at the graph first. http://www.wolframalpha.com/input/?i=plot+y+%3D+e%5Ex%2C+y+%3D+2x%2B1%2C+-2+to+1 I is obvious that y = e^x and y = 2x+1 intersect at the y-axis at (0,1). there is another intersection but it beyond x = 1, so of no concern to us So area = ∫ (e^x...
*November 25, 2014*

**Geometry**

In the actual case they had 18° So in the general case they now have x° So let's do exactly the same thing So if we have n sides and the exterior angle is x° then the interior angle is 180-x So (180-x)n = (180)(n-2) 180x - nx = 180n + 360 solving for n: 180x - ...
*November 25, 2014*

**math show work please**

Did you notice that x^2 + 8x + 15 = (x+3)(x+5) which happen to be the denominators on the left side So let's multiply everybody by (x+3)(x+5) (x+5) + 4(x+3) = 2 Now how easy is that from there ?
*November 25, 2014*

**math show work please**

1 - 11/x + 30/x^2 = 0 times x^2 x^2 - 11x + 30 = 0 (x-5)(x-6) = 0 x = 5 or x = 6
*November 25, 2014*

**calculus**

s = (3+6t)^(1/2) v = (1/2)(3+6t)^(-1/2) (6) = 3(3+6t)^(-1/2) a = (-3/2)(3+6t)^(-3/2) (6) = -9(3+6t)^(-3/2) when t = 1 a =-9(9)^(-3/2) = -9(1/27) = -1/3 you are correct!
*November 24, 2014*

**trig**

Oh my! I know that cos π/3 = 1/2 and cos π/6 = √3/2 (What is the matter with me ? )
*November 24, 2014*

**trig**

1. 4cosx = 2 cosx = 2/4 = 1/2 I know cos π/6 = 1/2 , so x = π/6 but the cosine is positive in quadrants I or IV so x is also 2π- π/6 = 11π/6 #2 sec^2 = 4/3 1/cos^2 x = 4/3 cos^2 x = 3/4 cos x = ± √3/2 so x could in any of the 4 quadrants ...
*November 24, 2014*

**MATH**

I got 12 Make a Venn diagram consisting of two intersecting circles, one called M, the other called L Put a rectangle around the circles. place 5 in the intersection of M and L since M contains 18 , but 5 are already written down, place 13 in the M only part of the circle. ...
*November 24, 2014*

**Math**

What is 10000(1.01)^72 ?
*November 24, 2014*

**calculus**

dy/dx = 2x - 6 = 0 for horizontal tangent 2x-6 = 0 2x=6 x = 3 , which is choice a)
*November 24, 2014*

**algebra**

ratio of x and y coefficient of first = 2 : 5 ratio of x and y coefficients of 2nd = 4 : 10 = 2:5 but the constants are not in that ratio, so you have two parallel lines
*November 24, 2014*

**Math**

This is my interpretation of the question: R-- right W -- wrong there are 8 ways for the selection to take place (or there are 2 ways to pick the first cheese, right or wrong, 2 ways to pick the 2nd, and 2 ways to pick the third: 2x2x2=8 ) WWW WWR ** WRW ** WRR RWW ** RWR RRW ...
*November 24, 2014*

**math**

let the acceleration be a , (I expect a to be negative) v = at + c when t = 0 , v = 8 8 = 0+c ---> c = 0 so v = at + 8 when t = .36, v = 0 0 = a(.36) + 8 a = -8/.36 = appr -22.2 m/s^2
*November 24, 2014*

**Precalc 2**

Can't see your diagram, but it looks like a straightforward cosine law R^2 = 1600^2 + 3200^2 - 2(1600)(3200)cos 135° R = ....
*November 23, 2014*

**Math (trigonometry)**

1. angle A = 180-17.9-108.1 = 54° now by the sine law: AB/sin17.9 = 472/sin54 AB = 472sin17.9/sin 54 = .... 2. (9,2)dot((-3,3) = √85√18cosØ , where Ø is the angle between them (-27 + 6)/(√85√18) = cosØ I got Ø = 122.5°...
*November 23, 2014*

**Calculus**

Of course ! For some reason I was thinking x = 0. Ignore my silly comment , ( I will blame it on "old-timers syndrome" )
*November 23, 2014*

**Calculus**

What about the constraint of y = 0 wouldn't that restrict the volume to the part on the left of the y-axis ? and using washers, we would get only v = π∫[-2,0]((2-x)-(-2x)) dx = 2π
*November 23, 2014*

**mathematics of investment**

I = PRT 8000(.09)T = 180 T = .25 years or 91 days I will leave it up to you to calculate what date that is
*November 22, 2014*

**Math**

counting the first bounce at up and down ... we have 144 + 144(2/3) + 144(2/3)^2 + ... which is an infinite geometric series where a = 144 , r = 2/3 sum(all terms) = a/(1-r) = 144/(1-2/3) = 144/(1/3) = 432 cm
*November 22, 2014*

**Maths**

then (3x+10)/(7x) = 6:7 42x = 21x + 70 21x=70 x = 70/21 = 10/3 so the number of reds originally was 3(10/3) = 10 the number of blues originally was 7(10/3) = 70/3 ????? how can we have partial balls ? I think there is something very wrong with your question. notice that "...
*November 22, 2014*

**Maths**

original red --- 3x original blue --- 7x number of reds added -- a number of blues added -- 10-a (3x+a)/(7x + 10-a) = 6/7 42x + 60 - 6a = 21x + 7a 21x - 13a = -60 I think you have something missing in your problem, maybe a typo We have to know how the 10 balls are distributed ...
*November 22, 2014*

**Math Check please**

your equation of c = 36/d^2 is correct so your constant of proportionality is 36 (your k value) now just plug in d = 5 c = 36/25 or 1.44
*November 21, 2014*

**Math**

the diagram looks rather routine draw the smaller building and mark is as 12 m high draw the other building a bit taller . draw a horizontal from the smaller to the taller, label the difference in height as x draw in your cable, Don't you have a right-angled triangle with ...
*November 21, 2014*

**Math**

(4^x)-(2^x)=56 (2^2)^x - 2^x - 56 = 0 (2^x)^2 - 2^x - 56 = 0 let 2^x = t , we get t^2 - t - 56 = 0 (t-8)(t+7) = 0 t = 8 or t = -7 if t = -7 2^x = -7 , no such x exists or if t = 8 2^x = 8 -----> x = 3
*November 21, 2014*

**Math**

3^(2c+1)=28*(3^c)-9 3^(2c)*3^1 = 28*3^c - 9 3(3^c)^2 - 28(3^c) + 9 = 0 let 3^c = x 3x^2 - 28x + 9 = 0 (3x - 1)(x - 9) = 0 x = 1/3 or x = 9 if x = 1/3 3^c= 1/3 = 3^-1 -----> c = -1 if x = 9 3^c = 9 = 3^2 ----> c = 2
*November 21, 2014*

**Math**

a) is correct b) since the S and L are defined variables, taken the inverse in the usual way changes their definitions. We could just follow the usual steps ... if S = 2√(5L) , the inverse is obtained by interchanging the variables, so inverse is L = 2√(5S) we ...
*November 21, 2014*

**Math Question**

-1500/360 = -4 with a remainder of -60° So we would have 4 clockwise rotations with and angle of 60 into quadrant IV
*November 21, 2014*

**Math**

f(f(x)) = f(6/(5+x) ) = 6/(5 + 6/(5+x) ) = 6/( (25+5x+6)/(5+x) ) = (30 + 6x)/(31 + 5x) = g(x) let y = (30+6x)/(31+5x) inverse is : x = (30+6y)/(31+5y) 31x + 5xy = 30 + 6y 5xy - 6y = 30 - 31x y(5x - 6) = 30-31x y = (30-31x)/(5x-6) = g^-1 (x)
*November 21, 2014*

**Math**

81^x = 64 log 81^x = log 64 x log81 = log64 x = log64/log81 27^(log64/log81 + 1) = 610.940...
*November 21, 2014*

**typo - Algebra**

forgot the zero in the first line , should read: as x is hugely negative, 2*51^x ----> 0
*November 21, 2014*

**Algebra**

as x is hugely negative, 2*51^x ----> so f(x) ----> 3 - 0 or 3 as x becomes hugely positive -2*51^x --->- ∞ do the range is y < 3 I will let you use whatever notation you have learned
*November 21, 2014*

**Math**

P(1.04)^10 = 5000 solve for P
*November 21, 2014*

**Math**

Rachel, Rachel ! Since both Damon and I went farther than the question asked for and also found the value of a .... all you needed is r = 1/2 (the value of a indeed has √2 in it, but your teacher was not referring to a but rather to r . Note we both had that √2 in ...
*November 21, 2014*

**Math**

ahh, so we have two ordered pairs (2,1) and (32, 4) that satisfy our equation ----> 1 = a(2)^r ----> 4 = a(32^r a(32)^r = a(2)5r so a(2)5r = 4 and a(2)^r = 1 divide them 2^(5r-r) = 4 2^4r = 2^2 then 4r = 2 r = 1/2 back into the first: a(2)^(1/2) = 1 a√2 = 1 a = 1...
*November 21, 2014*

**Math**

where does r come in ? did you mean , find a ?
*November 21, 2014*

**Algebra Help please!**

amount owing at 12% compounded annually in 4 years = 6000(1.12)^4 = 9441.12 amount owing at 12% per annum compounded quarterly in 4 years = 6000(1.03)^16 = 9628.24 Now subtract them as Henry told you to do.
*November 21, 2014*

**math please help!!!!!**

Since you are telling me that 4i = k then f(x)=x^3+(12-4i)x^2+(32-48i)x-128i =x^3 + (12 - k)x^2 + (32 - 12k) - 32k and since k is a zero, then (x - k) is a factor by synthetic division: f(x)=x^3+(12-4i)x^2+(32-48i)x-128i = (x-k)(x^2 + 12x + 32) = (x - 4i)(x^2 + 12x + 32)
*November 21, 2014*

**Algebra 2**

I will assume that you have (√5 + i)/(√5 - i) those brackets are absolutely essential. I will also assume that you want this rationalized. (√5 + i)/(√5 - i) = (√5 + i)/(√5 - i) * (√5+i)/(√5 + 1) , I am merely multiplying by 1, ...
*November 21, 2014*

**Math Help!!!**

If you meant √-75 , then you can't have a real number thus to ask for the nearest integer would be silly So you must have meant -√75 = -8.66025... = -9 to the nearest integer (look at the number on a number line)
*November 21, 2014*

**Math**

Brackets are essential here .... h(x) = (3x+2)/(7x-6) or y = (3x+2)/(7x-6) step 1 of finding the inverse is to interchange the x's and y's x = (3y + 2)/(7y - 6) 7xy - 6x = 3y + 2 step 2 : solve this for y 7xy - 3y = 6x + 2 y(7x - 3) = 6x + 2 y = (6x + 2)/(7x - 3) , ...
*November 21, 2014*

**Algebra 2**

from the type of problem that you posted, you surely MUST know how to solve quadratic equations. Steve took you as far as 5x^2 - 16x + 6 = 0 and made the same assumption I made. I suggest using the quadratic formula. (you will get two irrational answers)
*November 21, 2014*

**MATH**

proceed this way: f(g(x)) = f(2x^2 - 1) = 2/(2x^2 - 1) test it for some number e.g. let x = 3 g(3) = 18-1 = 17 f(g(3)) = f(17) = 2/17 in my answer: 2/(2x^2 - 1) = 2/17 This does not 'prove' that my answer is correct, but there is high probability that it is. Had my ...
*November 21, 2014*

**math**

old rate --- $x new rate --- $ x+2 wage per week at old rate = $ 32x wage per week at new rate with more hours = 40(x+2) 40(x+2) - 32x = 200 easy to solve
*November 20, 2014*

**Math Help**

Think about it .... if perimeter of little square is 16, each side is 4 for the larger, each side is multiplied by 7, or , each side is 28 so perimeter of larger is .....
*November 20, 2014*

**algebra. help!**

How can I check your work if you did not supply any of your choices
*November 20, 2014*

**math**

your solution is correct to check, you must go back to the original equation LS = log4 (19-3) = log 4 (16) = 2 -----> what must be exponent on 4 to get 16 ? = RS so x = 19
*November 20, 2014*

**Math**

Let his original number of pens be x then his original number of pencils is 30 - x So for every pen he gets 2 pencils so x pens will yield him 2x pencils but he already had 30-x pencils, so 2x + 30-x = 48 x = 18 So, originally he had 18 pens and 12 pencils check: 12+18 = 30 , ...
*November 20, 2014*

**math**

of course not distribute ... -36 - 6x - 6x - x^2 = .... add like terms
*November 19, 2014*

**math!!!!!!**

just distribute ... x(x+y+2) = x^2 + xy + 2x
*November 19, 2014*

**Algebra**

I will assume you mean (1/25)^(x+2) = 125^-x or else we got ourselves one doosey of a problem (5^-2)^(x+2) = (5^3)^-x 5^(-2x-4) = 5^(-3x) then -2x-4 = -3x x = 4
*November 19, 2014*

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