Thursday

April 17, 2014

April 17, 2014

Total # Posts: 21,708

**Algebra**

4(6x^2-x-2) 4(3x+2)(x-1)

**Math Geometry**

x * (5/4)x = 180 x^2 = 144 ...

**Calculus Help Please!!!**

y' = 8x-6x^2 so, at x=a, y' = 8a-6a^2 = m Use the above info to plug into the point-slope form of the lines. No sweat.

**Math**

The key here is to recognize that opposite angles are supplementary. So, BAD+BCD = 180 2BAD=3BCD, so BCD = 2/3 BAD 5/3 BAD = 180 BAD = 108

**Calculus Help Please!!!**

(c) (15005-10237)/2 = 2384 (d) (16684-12435)/2 = 2124.5 (e) Looks like growth is slowing down

**Algebra - help**

just add them up: 3.1x^2+6x+0.3 4.2x2-5.2x+1 ---------------------- 7.3x^2+0.8x+1.3

**Algebra**

well, just plug it i: S = 4 pi (4x+1)^2 now just expand that

**Math**

n Tn 1 3*1+5 = 8 and so on actually, assuming one choice is correct, only B is a candidate.

**math**

(7y+4)(y-8)

**Math - incomplete**

well, with the four scores given, the average is already 75. I think some info is missing.

**Math**

since the period is 60/3.6 seconds, and reaches a max at t=12 seconds, y = 35cos(2pi/(60/3.6)(t-12))+51 which agrees with your formula. You have found y at t=8 seconds, not 8 minutes.

**math**

(6-4.5)/4.5 = 1/3

**Science**

Felipe made a toy boat out of clay, but it kept sinking in water. He changed the boat's design by making it slightly wider than before. Why did Felipe's newly designed boat float on water? A. He decreased the density by increasing the volume. B. He decreased the densit...

**Trigonometry**

C = 24pi in = 2pi ft (20 ft/s)/(2pi ft/rev) = 10/pi rev/s * 2pi rad/rev = 20 rad/s

**Trig**

no. sinA = 2 sinB

**math**

11/4

**Algebra word problems**

5x+20y = 175 x = 4y+3 Now just solve for x and y

**math**

yes

**math**

-y/6 < 2 y/6 > -2 y > -12

**math**

2/5 n = 4 n = 10

**Algebra 1**

RA = 11 RT = 1

**Math**

since the height of the ball is y = Ho + (tanθ)x - g/(2 (v cosθ)^2) x^2 y = 50 + .1175x - .000563x^2 Just solve for θ in 50 + (tanθ)(420) - 16/(2(120 cosθ)^2) * 420^2 = 0 I get θ = 6.7°

**Algebra**

7x*11x - 2x*3x = 71x^2

**Math**

1/2 dozen, no?

**Polymonial help**

Can you not? My factorization gives the three dimensions. Look at the last choice.

**Polymonial help**

factor the polynomial and you have y(y-6)(y+1) so, as long as y>6 some possible dimensions are 7x1x8 8x2x9 ...

**Math**

compare the times. The time it took to cover 100km at speed s is 100/s That was 1/2 hour more than the time it took to cover 100km at the faster speed, s+10

**Math**

since time distance/speed, 100/s = 100/(s+10) + 1/2 s = 40

**math**

(sum(r) for r=1..n)^2 - (sum(r) for r=1..n-1)^2 = n^3 well, we know that n ∑ r = n(n+1)/2 r=1 so, square that and we have n^2(n+1)^2/4 Sum to n-1 instead of n, and we have (n-1)^2 n^2/4 Subtract to get n^2/4 ((n+1)^2 - (n-1)^2) = n^2/4 (4n) = n^3

**ASCC**

25 m/s / 2.3 m/s^2 = 10.87 s distance = 25t - 1.15t^2 where t = 10.87

**Math**

no diagram. If the angles are alternate interior/exterior angles, then 5x+2 = 3x+28 If they are adjacent angles, then 5x+2 + 3x+28 = 180

**Math Help**

since the bus catches up 175 km in 5 hrs, that's a speed difference of 35 km/hr. So, the bus went 10+35 = 45 km/hr Your solution is in error. It should be 225km/5 hr = 45 km/hr (Also, the units are wrong in your 1st line: 10km/hr * 5 hr = 50 km, not 50km/hr) another soluti...

**Geometry**

That's what I get.

**math 100**

|3x-10) > 2 either 3x-10 > 2 3x > 12 x > 4 or -(3x-10) > 2 3x-10 < -2 3x < 8 x < 8/3 If you look at the graph you can see why an abs val > n problem usually has two solutions. http://www.wolframalpha.com/input/?i=+|3x-10|+%3E+2

**maths literacy - still incomplete**

no matter how many times you ask it, there is still not enough information to answer the question.

**math - incomplete**

none, if they all die.

**math 100**

50 < 40 + .25m

**Maths**

x + 2x-8 = 178

**math - eh?**

What's all this nonsense with ;;;? Just use + signs! If you mean the sum of x^2 / ((x-1)+x+(x+1)) that's kind of weird, since it boils down to x^2/3x = x/3 Naturally, the sum will be infinity. And what do you mean "find the value of x"? We are adding up all t...

**Math help, anyone?**

very good. B is the answer

**Math help, anyone?**

well, I just said that "right" refers to angles, not sides. So, #1 and #3 are out. Other kinds of angles are acute and obtuse. So, rather than just guessing, why not check on the terms being used?

**Math help, anyone?**

actually, a right triangle contains a right angle, so it does not fit into the category of triangles classified by sides. We aren't talking about angles. So, questioner, just look up the terms listed, and see which ones only talk about the sides of a triangle.

**algebra**

well, geez. The slope-intercept form is y = mx+b where m is the slope and b is the intercept. Which answer has slope 2/7 and intercept at y=12?

**Statistics**

Pick any person. There are 16 people to shake hands with. Since there are 18 people, there are 18*16 shakes. But, counting this way, each shake is counted twice, once for each person. So, the final answer is 18*16/2

**Surds please help!**

(√a + 3√b)/(a-b) - 2/(√a+√b) Note that (√a-√b)(√a+√b) = a-b, so (√a + 3√b)/(a-b) - 2/(√a+√b) * (√a-√b)/(√a-√b) (√a+3√b)/(a-b) - 2(√a-√b)/(a-b) (√a+3...

**function table**

well, what's 2*50 - 7 ?

**Maths**

n-30 = 14-3n n = 11

**Math**

26

**math**

If Mickey has x books, then x + 3x - 1 = 27 x = 7

**Inverse laplace**

Recall that L{tf(t)) = -F'(s) Since L^-1{1/(s-1)} = e^t and d/ds 1/(s-1) = 1/(s-1)^2 L^-1{1/(s-1)^2} = te^t

**pre-calculus**

147b^3-35b^2-19b+3 = 0 Since 147 = 7*7*3, I'd try using those coefficients first, since the inside coefficients are relatively small. A little playing around shows that T(b) = (7b-1)(7b-3)(3b+1)

**algebra**

Assuming you want the length of each piece, 1/2 = 9" 3/4 of that is 6 3/4 " The rest is thus 2 1/4 "

**math**

k(1-3/7) = -6/7 4/7 k = -6/7 4k = -6 ... 6.4x-x = -3.4+3.5 5.4x = 0.1 ...

**math**

900*1600*3 * 5.20

**math**

#1 depends on how many he wants to by count * cost <= 35.0 #2 4h <= 25

**math**

use the scale which allows both dimensions to fit: 8.5/100 or 11/150

**MAT-134 Math XL**

3x^7 - 9x^6 + 24x^5 3(x^7-3x^6+8x^5) 3x^5(x^2-3x+8)

**Math**

you can find Z-table help here: http://davidmlane.com/hyperstat/z_table.html you know the mean is midway between these two extremes. Use the tool to find how many STD's that is, then scale up to find the real score range.

**algebra 1**

x^5 + 5x^3 + 4x - 8 descending powers of x

**Math**

pick any value for x. Small values are easy to work with. Calculate the value for y. Plot the point. x y -4 3 -3 0 -2 -3 -1 -4 0 -3 1 0 2 3

**Algebra 2**

4/3 pi (r+6)^3 = 4/3 pi r^3 + 336pi 4(r+6)^3 = 4r^3 + 1008 now just solve for r

**Math help**

well, no. If the product of some numbers is zero, then one of the numbers must be zero. We have (3s-4)(2s-3) = 0 So, we must have either 3s-4 = 0 or 2s-3 = 0 So, s = 4/3 or 3/2 Had you tried your guesses in the original equation, you would have seen they did not satisfy it.

**Math help**

set everything to zero, then you can factor. #4 6s^2-17s+12 = 0 You know the factors will look like (6x-?)(x-?) or (3x-?)(2x-?) So, since -17 is fairly large, we will probably have the first (6s-3)(s-4) gives -27s too big (6s-4)(s-3) gives -22s still too big (6s-6)(s-2) gives ...

**Math**

Hmmm. x^4 + 10x + 18 - (x^4 - 3x + 2) does equal 13x+16 see what a difference some parentheses can make?

**calculus**

Hmmm. I get y = -x^3+bx^2+cx+d y' = -3x^2+2bx+c y" = -6x+2b inflection at x = -2 means -6x+2b = 0 b = -6 y = -x^3 - 6x^2 + cx + d extrema at x = -5,1 y' = (x+5)(x-1) = x^2+4x-5 we need -3x^2, so y' = -3x^2-12x+15 so c = 15 y = -x^3 - 6x^2 + 15x + d f(2) = 11, ...

**Math**

well, if yo know the measure of angle 5, then you can solve for x. For instance if <5 = 50°, x=13

**Algebra**

A taller people usually weigh more

**Algebra**

what association would you expect if you were graphing height and weight a- positive b- non-linear c- negative d- none of these my answer is a

**Agent HELP! Trigonometry**

Draw the altitude to the base. Then, if the angle is x, sin(x/2) = 5/17 now you know x/2, so just double it.

**Trigonometry**

sin67° = .92 48*.92/58 = .73 so, now you know sin A = .73 no sweat to find A now, eh?

**algebra**

reseller, not "retsilor" algebra, not "a" 15 * 1.30 = ?

**math**

local/foreign = 7/4 (local-8)/(foreign-8) = 9/5 local = 224 foreign = 128 now find your answer.

**Math 110 - incomplete**

depends on how many you have already taken.

**Algebra**

just multiply them all together.

**Math**

well, how many tiles does it take to cover a side and an end? Double that and add one for each corner.

**Alg help**

I get √241 = 15.52

**Algebra 2**

Plug in the (x,y) values and see whether they fit your equations. -3(-5) + 1 = 6? No (1/2)(1) - 3/4 = 4? No (5/3)(5)-17/3 = 10? No Try again, and show your work; you evidently need some coaching and study.

**math please help**

T >= -20

**math**

plug in your data at http://davidmlane.com/hyperstat/z_table.html It is an excellent tool

**Math**

the slant height is the height of each triangular face. Since you know how to find the area of a triangle, multiply that by 4, the number of faces.

**algebra - incomplete**

Got to know how high the 30th floor is.

**Algebra**

what is the formula used to calculate the lateral area for a square pyramid?

**Algebra**

what is the formula used to calculate the surface area for a square pyramid?

**Algebra**

what solid has 2 bases that are triangles and 3 lateral surfaces that are rectangles a- triangular pyramid b- rectangular prism c- triangular prism d- rectangular pyramid my answer is C

**Algebra**

if you go calc101.com and click on the long division link, you can see all the details and try other examples.

**algebra**

since y/x is constant, 2.52/8.4 = y/2.7 y = 0.81

**Math**

You have to ask yourself how much work gets done in 1 minute. Mr Baily can do 1/90 of the total in a minute. Add to that the amount that his son does in a minute. The sum is how much of the job gets done by both together. SO, if 1/3 gets done in a minute, the job takes 3 minut...

**Math**

1/x = 1/90 + 1/75 x = 40.9

**Math**

correct

**algebra**

no if there are any constant terms, the variation is not direct. You need y = kx for some value of k

**math**

If there were 5 tests, with average a, then compare total points earned: 5a - 60 = 4(a+5) 5a-60 = 4a+20 a = 80

**math**

current value is 10d+25q 10d+25(1.1q) = 1.075(10d+25q) 10d + 27.5q = 10.75d + 26.875 .625q = .75d q/d = .75/.625 = (3/4)/(5/8) = 6/5

**geometry**

h/2.8 = sin 25°

**Maths**

correct, if you meant 170,000

**math**

ʃ 1/4 sin^2(2x) dx = 1/8 ʃ 1 - cos(4x) dx = 1/32 (4x - sin 4x) + C

**pre calculus**

assuming a proper allocation of papers and distance, then 1/x = 1/70 + 1/80 x = 112/3 minutes

**pre calculus**

1000x + 2000(x+.005) = 190 x = 6%

**Math**

draw a diagram, as usual. If the tower has height h and the wire is meets the ground at distance d, h/d = sin 52 h/(d+32) = sin 21 eliminate d and you have h/sin52 = h/sin21 - 32 now just solve for h

**Math**

1/2 pi (24/2)^2 = 72pi in^2 Maybe in this case it actually should be 72 pie !

**math**

If you mean (as in area of trapezoid) h = 2A/(b1+b2) hb1 + hb2 = 2A hb1 = 2A-hb2 b1 = (2A-hb2)/h

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