# Posts by STEVE

Total # Posts: 50,466

**Math**

Assuming 182 days in 6 months, we have 1637/182 = 0.003x

**algebra**

Use your terms carefully. Consider that growth of 50% give a result 1.5 as big as the starting value. So, growth of 174% gives a result 2.74 times as big. 51 * 2.74 = 139.74 cm Make sure that's how you intended to phrase the question.

**Math**

The short side is 4/5 as long as the long sides. So, they are 5/4 as long as the short side. 2 * 5/4 x + x = 15.4

**maths**

multiply top and bottom by the conjugate, and you get (3+?5)(2+?5) ------------------ (2-?5)(2+?5) = (11+5?5)/(4-5) = -11-5?5

**maths**

To avoid writing all the powers of 1, let's agree that they are all just 1. So, (1+x)^(1/4) = 1 + (1/4)x^1 + (1/4)(-3/4)/2! x^2 + (1/4)(-3/4)(-7/4)/3! x^3 + ... = 1 + x/4 - 3x^2/32 + 7x^3/128 - ...

**word problem**

6800-6400 = 400 So, the population rises by 200 each year. Go with that...

**Math**

Assuming the three groups are disjoint, then there are 545 total students. So the central angle you want is (190/545) * 360°

**calculus**

Since ?y/?t is the slope of the line approximating the curve, the ?y is just the slope times ?t So, if dy/dt = f(t) yk+1 = yk + f(t)*?t

**Algebra 2**

17 ? 3+7k k=0 S18 = 18/2 (2*3+17*7)

**Precalculus**

Assuming the usual sloppiness with parentheses, I'll assume that f(x) = (3x-4)/(x+2) = -10/(x+2) + 3 so you appear to be correct, with the caveat that the stretch is done before the upward shift.

**pre calc**

So, are you Ruth or Beth? You don't say whether the observers are shining lights in the same direction or opposite directions. I'll assume the same direction (the 2nd observer is behind the 1st one). In that case, h cot45° - h cot75° = 600 If the lights are ...

**Pre calc**

the tower's height can be considered in two pieces: above the window, and below the window. So, it is 375*tan39° + 375*tan25° = 303.669 + 174.865 = 478.534 or, 479 You only calculated the height above the window. They gave you the second angle for a reason, but you...

**precal**

swap values, and you need (2,?),(4,?),(8,?) where the ?'s must match the 1st numbers

**Algebra**

I don't know about "simplify" bu to expand it, try this: You know that (a-b)(a+b) = a^2-b^2 (a-bi)(a+bi) = a^2+b^2 So, (x+1)(x(-4-5i))(x-(4+5i)) = (x+1)((x-4)-5i)((x-4)+5i) = (x+1)((x-4)^2 - (5i)^2) = (x+1)(x^2-8x+16 + 25) = (x+1)(x^2-8x+41) = x^3-7x^2+33x+41 =

**math**

P(navy) = 1/2 how many total sizes? How many 10 or larger? P(navy & >=10) = P(navy)*P(>=10)

**math 8**

yes. That is how binary numbers are formed.

**Math**

?r^2 = 120 so, solve for r.

**precalc**

(a) 3-hr factor is 0.41 m^3 = 0.41 (b)m = 0.743 (c) m^6 = 0.41^2 = 0.168 (d) 15min = 1/4 hr, so that is m^(1/4) = 0.928

**Math 120**

Of the 6 outcomes, 2 are not greater than 2. So, the odds are 2:4 = 1:2

**Science**

(75*9.8)(5.12*0.2)/5

**Precalculus**

a little synthetic division yields factors of (x-2)(x+6) so, divide that out and you are left with (x^2+2)

**Math**

well, at 3:00 they form a right angle...

**Pre-cal**

as always, draw a diagram. Then it should be clear that the distance is 500 cot32° + 500 cot23°

**Math**

I assume your two equations are y = 4x+8 y = x^2+7x-20 So, just set them equal: x^2+7x-20 = 4x+8 x^2+3x-28 = 0 (x+7)(x-4) = 0 x = -7 or 4 See http://www.wolframalpha.com/input/?i=x%5E2%2B7x-20+%3D+4x%2B8

**math**

2 cups = 8/4 cups That is 11/4 = 11/8 * 2 So, you will need 11/8 as much milk. 11/8 * 3/4 = 33/32 cups milk. Or, 1 cup + 1/2 tbsp.

**Math - typo**

rate. make that 6^2 + 4*(6*4)/2 = 84

**Math**

well, it sounds like the triangles have two sides of length 5, and an altitude of 4. That means, each triangle consists of adjoining 3-4-5 right triangles, making a base of 6, which is also the side of the square. So, the area of the pyramid is 4^2 + 4*(6*4)/2 = 64

**Math**

A net is an unfolding of a line drawing of the pyramid. Each line represents an edge of the original figure. So, they will give a way to determine the dimensions and thus the area and volume of the pyramid. If you google "square pyramid net" you will see lots of ...

**Math**

well, what do the lines on the net represent? The surface area is the area of the square base, plus 4 isosceles triangles.

**Trigonometry**

see your previous post, in related questions below. Also, recall that tanA = sinA/cosA

**math please help me out fam**

#1,#2 use any online grapher, such as wolframalpha.com #3 well, what do you have to add to 4 to get to -4? (4,-4) + (-8,?) = (-4,7) #4. Put the words into algebra: T: (x,y) -> (x-4,y+1) ... #5 no figure available #6 to reflect in the x-axis, change the signs of the y-...

**physics help**

Knowing the radius of the circle is not enough. Is it a full semi-circle, or a smaller section? A speed bump 1cm high will not do much.

**calculus**

if the NS sides have length x and the EW sides have length y, then if he spends the entire $500, 2*4x + 2*8y = 500 or, 2x+4y=125 A = xy = x(125-2x)/4 This is just a parabola, with its vertex (maximum area) at (125/4, 15625/32) For #b, y=1878/x, so the cost c is 8x+16y = 8x+16(...

**Trigonometry**

cosA = -3/5 so A is ins QIII sinA = -4/5 now the rest is easy...

**math help? burnet help.**

1/(4x) takes 1/4 as long to get to the same y, so the graph is compressed by a factor of 4 horizontally. the rest is easy ...

**Algebra 1**

how is 3^5^2 a radical? Looks like exponents to me. 3^5^2 = 3^(5^2) = 3^25 no idea where a enters the picture ...

**Algebra 1**

If x sold early, and y sold on the day, then x+y <= 800 6x+9y >= 5000

**Physics**

review your text. I'm sure it says that 1/R = 1/15 + 1/10

**math**

There are 10 fruits. P(banana) = 1/10 since there is only one banana. After the 1st pick, there are only 9 fruits left. Now it should be clear what P(pear) is. P(both) = P(banana) * P(pear)

**Math**

let u = 3^x. Then you have u - 1/u - 1 = 0 u^2-u-1 = 0 solve for u, and then x = log3u

**Math**

measuring from the tower, if the distance away is x, and the rocket had risen to a height h when first observed, h/x = tan25° (h+4)/x = tan66° Now you can solve for x.

**math**

note that x^2+25 = (x-5i)(x+5i) The exponents on the factors are the multiplicities.

**Precalculus**

(x+1)(x-(4-5i))(x-(4+5i)) now just expand that

**Math**

(a) 500(1/2)^t (b.1) 500(1/2)^(25000/5730) = 500(1/2)^4.363 = 24.3 see what you can do from here.

**Precalculus**

y = (x-4)(x-7i)(x+7i) now just expand that.

**math 1**

rubbish. If you followed the steps, what were they?

**math 1**

so, what were your calculations? If we are to analyze why your answer may be wrong, show us how you got it.

**AP physics (multiple choice)**

v is changing direction, and a is also changing direction. so, what do you think?

**Just Curious**

take a look at some of the questions and the responses. You decide.

**Precalculus**

Assuming you mean real coefficients, then D

**Precalculus**

complex zeroes occurs in pairs, so ...

**math**

X/Y = A/B X/Y + 1 = A/B + 1 (X+Y)/Y = (A+B)/B (X+Y)/(A+B) = Y/B

**Math**

area scales as the square of the ratio. So, the square of the ratio is (125/20) = 25/4. So, the ratio is 5/2 Volume scales as the cube of the ratio, or 125/8

**math**

yes no - positive powers only. the leading term is usually the highest power. The constant term is just a number, with no variables.

**math**

in terms of Friday time, Sat at 2:26:33:07 = 26:26:33:07 So, just subtract 26:26:33:07 -7:44:35:16 to allow for borrowing, that's the same as 25:85:92:107 -7:44:35:16 --------------- 18:41:57:91

**Algebra**

note that each term has an x. So, factor it out: x(x+6)

**math**

2x^2-2x 2x^2-15

**math**

try adding: 2/7 + 1/3 = 13/21 so, 13/21 - 1/3 = 2/7

**maths**

1/4 = 16r^6 r = 1/2 16,8,4,2,1,1/2,1/4

**Geometry**

they are similar

**math**

a = 4?r^2 da/dt = 8?r dr/dt v = 4/3 ?r^3 = ar/3 dv/dt = 1/3 (r da/dt + a dr/dt) Now just plug in your numbers

**MATHS**

ever heard of math notation? (sin^4x-cos^4x)/(1-sin^2x) = (sin^2x+cos^2x)(sin^2x-cos^2x)/cos^2x = tan^2x-1

**Maths**

google is faster. For any pyramid, v = 1/3 Bh where B is the area of the base.

**Maths**

v = 1/3 Bh, so 100 = 1/3 B * 12 Now solve for B, the area of the square base, and then the side is easy

**calculus**

assuming you want to integrate, let u=ln(3+x) dv = x dx du = 1/(3+x) dx v = x^2/2 ?u dv = uv - ?v du ?x ln(3+x) dx = x^2/2 ln(3+x) - 1/2 ?x^2/(3+x) dx Now just divide, and you will have easy stuff left.

**calculus**

let u = (lnx)^2 dv = x^-3 dx du = 2lnx/x dx v = -1/2 x^-2 ?u dv = uv - ?v du ?(lnx)^2/x^3 dx = -(lnx)^2/(2x^2) - ?(-lnx)/(x^3) dx Now repeat with u=lnx and you will be left with just a power of x to integrate.

**Precalculus**

since complex roots occur in conjugate pairs, (x-3)^2 (x-(5+i)) (x-(5-i))

**Precalculus**

y = (x-2)^2 (x+4)^3 now just expand that.

**Fraction**

48

**Math**

Let's make things easy by ending up with 21L of the 1:20 solution. That will contain 1L of pure solution. (2/7)x + 0(21-x) = (1/21)(21) x=7/2 So, mix 3.5L of the 2:5 mixture with 17.5L of water

**physics homework**

depends on the spring constant. asking twice won't help ...

**Algebra**

1200 * e^(.05*6) = 1619.83 too bad you didn't include your work ...

**Math**

2^2(7+2^2)+0*1 71-(20+7) There are lots of ways

**Mathematics**

If (x-1) is supposed to be the altitude, then (x+6 + 3x-4)/2 * (x-1) = 119 x = 8

**Maths**

Huh? LCM(140,n) has to be at least 140...

**Maths**

you are correct. I misread the problem. Can you see where?

**Maths**

(2x+2x+2x)-(10+19+29)+x = 90 Hmmm. I suspect a typo.

**Chemistry**

see related questions below

**Science**

(30m/s)/(60s) = 0.5 m/s^2

**physics**

The resistance of the parallel component is 30R/(R+30) If R' is the equivalent resistance of the circuit, R' = 1/(1/30 + 1/R) + 6 = 36(R+5)/(R+30) The current through the 6? resistor is 120/R' = (10R+300)/(3R+15) The voltage drop across R is [30R/(R+30)]/[36(R+5)/(...

**Math**

T13/T6 = ar^12/ar^5 = r^7 (3/16)/24 = 1/128 = (1/2)^7 so, ...

**maths**

506 base 6 does not exist, since base 6 numbers consist only of the digits 0-5.

**Math**

use the law of sines to show that the base is divided into equal lengths. Then that will imply that the angles at the base of the altitude are also equal, so they are both 90 degrees.

**math**

50 * (1788/3725)

**algebra**

just solve the equation x^2 + (1/2 x + 11)^2 = (2x+1)^2 x = 8

**college algebra**

C(x) is just a parabola. Its minimum value is at the vertex, where x = -b/2a = 7

**math**

90 years is 3 half-lives. That means that 1/8 of the original amount remains. So, the 1 mg that has decayed represents 7/8 of the original amount. So, starting out at 8/7 g, 1/7 g = 14.27mg remains. ---------------------------------- after 4 half-lives, 1/16 of the original ...

**college algebra**

Sorry, that -3072 means its initial height (at t=0) is 3072 feet below ground.

**Math**

since |y| > y, y < 0, so |y| = -y x>|y|, so x+y>0 ==> |x+y| = x+y |x+y|-|x|+|y| = x+y-x-y = 0

**Math**

4^x = 6 2^x = ?4^x = ?6 8^x = (2*4)^x = 2^x * 4^x = 6?6 or, 8^x = (4^(3/2))^x = (4^x)^(3/2) = 6^(3/2) = 6?6

**Math**

(A+B)/2 = A + B/10 A/2 + B/2 = A + B/10 A/2 = 2/5 B A = 4/5 B A.B = 4.5

**Calculus**

2?r^2 + 2?rh = 20 so, h = 10/?r - r the volume is v = ?r^2h = ?r^2(10/?r - r) = 10r-?r^3 so, find r when dv/dr=0

**Math**

If the walk has width w, then since the parkland occupies 80% of the area, (30-2w)(5-2w) = 0.80*30*5 w = 0.4396m

**Calculus**

h+4s = 14 v = hs^2 = (14-4s)s^2 so find s when dv/ds = 0

**Physics**

since V is constant, and PV=kT, P/T = k/V is constant. So, you want P such that P/(273+25) = 7/(273+15)

**math**

because 1/c = c^(-1)

**Math**

check your prior post in the related questions below ...

**Calculus please help!**

consider f'(1) where f(x) = ?x where you should have written the limit as (?(1+h) - ?1)/h

**Pre calculus**

p(x) = (x-11i)(x+11i) = x^2 - (11i)^2 = x^2+121

**Physics**

distance = speed * time so, time = distance/speed