# Posts by steve

Total # Posts: 53,610

**MATH**

check out associative

**math**

thnx its 45

**math**

use compatable numbers and then divide 448/8

**math**

You say the pool is 12m wide, but both ends are only 10m wide. I'll assume that's a typo, and the pool is 10m wide. The side view is a trapezoid with bases of 1.3 and 3, and an altitude of 40. So the volume of the pool is (1.3+3)/2 * 40 * 10 = 860 m^3 The volume of ...

**math helllppppp**

D is correct.

**Precalculus**

yeah, you already said that. But what does tangent to y=x+20(11,9) mean?

**Precalculus - eh?**

hmmm. I see a couple of straight lines, and what may be a point. I fail to see any circles or other curves involved. Maybe a little more explanation will help. Do you want the equation of a circle whose center is on y=1/3x+6, and is tangent to y=x+20? If so, where does (11,9) ...

**Math**

You have a sum of an arithmetic progression, where the common difference is 7. 50/2 (2a+49*7) = 12075 a = 70 70+49*7 = 413 So, numbers range from 70 to 413

**Maths**

3c = h c+h = 1600 now just find c and h.

**Maths**

the consecutive numbers are x, x+1, x+2 you are told that x + x+1 = 39 + x+2 solve for x and you're almost done.

**math**

there are six faces on the box. two of length x breadth two of length x height two of breadth x height so, just use your dimensions and crank out the products.

**Physics**

I agree except for B. People are mammals, which have internal body heat regulation. They maintain roughly the same temperature regardless of environment. Reptiles and other cold-blooded animals cannot do this, and their internal temperature is much more greatly affected by ...

**Algebra**

notice that 2 is a factor of each term. So, factor it out. 2(x+y)

**math**

age now: x age in 5 years: x+5 age 5 years ago: x-5 so, write the words in math x+5 = 2(x-5)^2 now just solve for x. Since you have a quadratic function, you will get two answers. Only one answer will make sense.

**Calculus**

by x=1,2 do you mean 1.2 or 6/5? Anyway, the volume from x=a to ? is ?[a,?] ?y^2 dx = ?[a,?] ?/x^2 dx = ?/a

**Calculus**

do you want the arc length (above and below the x-axis), or the surface when the arc (above or below the axis) is rotated about the x-axis?

**Algebra**

Terms are separated by + and - signs. There are six terms in your expression. Either they answer key is wrong or you have a typo.

**AP Calc**

f(1) = 0/0, so (x-1) must be a factor of both the numerator and denominator. f(5) = 0, So (x-5) is a factor of the denominator only. f(2)=0, so (x-2) is a factor of the numerator only. f(x) = a(x-1)(x-2)/(x-1)(x-5) for x?1 f(x) = a(x-2)/(x-5) as x->1, f(x) -> -1/9, so a...

**Math**

3/7 of 49 = 21, so there were 21 boys. saying "the rest were girls" is redundant; what else could they be? It's just noise, put in to obfuscate the issue and try and confuse you.

**Maths**

There is no way to "solve" this. It is just an expression, since you have failed to complete the equation. Even if you take care of that, and you wind up with an equation such as 9y+2x = 13 That equation represents a line. You can pick any value of x (or y) you want...

**Maths**

yep.

**Maths**

the final displacement is 350m south 200m east the distance is thus ?(350^2+200^2)

**Maths**

dividing evenly gives 10,10 To make the difference 8, subtract 4 from one side and add it to the other: 6,14

**math**

2?*93*10^6 mi/yr * 5280 ft/mi * 1yr/365.25 day * 1day/86400s = 97767 ft/s

**math**

since the diagonals are equal, 5x+2 = 4x+7 x = 5 Knowing the diagonals does not help in determining the lengths of the sides. However, if we go with integers, then the halves of the rectangle are 3-4-5 right triangles. So, the perimeter is 2(3+4) = 14.

**Mensuration**

since 1kL = 1m^3, v = ?r^2 h 16?h = 1408 h = 88/? m

**algebra**

2/3 * 3/4 * 1/5 = 1/10

**math**

In the hours that have passed since you first asked this question, you could have spent 30 seconds with google and found what you needed. For instance, https://learnzillion.com/lesson_plans/8580-prove-two-figures-are-similar-after-a-dilation

**math**

AB: (y-2) = (p-2)/(k-3) (x-3) CD: (y-3) = (p-1)/(k+3) (x+4) At (1,-2) we have -4 = -2(p-2)/(k-3) -5 = 5(p-1)/(k+3) -4(k-3) = -2(p-2) -5(k+3) = 5(p-1) now just solve for k and p.

**Maths**

I suspect a typo. As it stands, the identity is false. Just plug in, say, pi/4.

**math**

2h15' + 1h30' = 3h45' = 3.75 or 3 3/4 hrs (3 3/4)/24 = 5/32 day

**Maths**

If the numbers are x1-x10, then the median is (x5 + x6)/2 = 10 Since the range was less than 4, that means that the numbers in order were 8 x x x 9 11 11 11 11 11 or 9 9 9 9 9 11 x x x 12 12 The median moved upward, so the even number was added on the top side, so it must have...

**math**

same thing, different numbers. You should recognize the hidden 3-4-5 right triangle in this one.

**math**

You have three sides of a right triangle. So the perimeter is 6.1 + 7.4 + ?(6.1^2+7.4^2) = 23.1 I have no idea what your 2nd post means.

**Differential equation**

since sec x is never zero, we can get rid of it. Now we have y' - x^2y^2 = 0 dy/y^2 = x^2 dx -1/y = 1/3 x^3 + c/3 y = -3/(x^3+c)

**Basic mathematics**

since sum(logs) = log(product) you have log(2*2^3/7^4) = log 16/2401

**Science**

well, you need A•B = 0 So, let B = A sin x >b>i - A cosx j

**Algebra**

what, no calculator? 5.57

**Maths**

(y - 3/2)^2 = (x + 9/4)

**Maths**

12x^3-8x^2+kx+18 = 0 If one root is a and the other is -a, then we have (with the third root being p) 12(x-a)(x+a)(x-p) = 12(x^2-a^2)(x-p) = 12x^3-12px^2-12a^2x+12a^2p So, we need -12p = -8 p = 2/3 12a^2p = 18 a^2 = 9/4 a = 3/2 k = -12a^2 = -27 check: (3x-2)(2x-3)(2x+3) = 12x^...

**Physics**

the round trip is 350 m. So, the speed of sound is 350m/s

**science**

the velocity changed by 30 m/s in 6 seconds. So, the acceleration a = -5 m/s^2 F = ma ...

**science**

PV=kT so, since T is constant, so is PV. You want P such that P*5 = 43*11 P = 94.6

**Economics**

How do falling prices affect supply? I'm having a hard time between either the supply curve moves to the left and the quantity demanded rises. I think the answer is that the quantity demanded rises.

**Math**

(4*2-2)^2/9+2 = 6

**math**

c*1.2 + 1.2 = c*1.4 c = 6

**Physics**

correct.

**algebra**

(x^2+1)^2 = x^4+2x^2+1 so, x^4+x^2+1 = (x^2+1)^2 - x^2 = (x^2+1+x)(x^2+1-x) No linear factors with rational coefficients.

**Science**

Use the 20N force as angle zero: <20,0> Then the 5N force is <-4.33,2.5> So, adding them up you get <15.67,2.5> Now just take the magnitude of that, and its direction angle ? has tan? = 2.5/15.67

**COMPUTER**

(x+y+z)/3 max(x,y,z) min(x,y,z) x+y+z

**Science**

what is the chemical composition of clay? and for polymers?

**Geometry Urgent Help plz!**

First, divide by 2. x^2-8x+18 = 0 the roots are provided by the quadratic formula: x = (8±?(8^2-(4*1*18))/2 You can see that they are complex because the discriminant is negative. So, there are no x-intercepts. The y-intercept is of course 36, since there, x=0. To find ...

**Math**

it is a family of lines through the center. See what you can do with that.

**maths**

If there are N animals in total, then there are N-55-65-50 pigs, assuming there are no other kinds of animals.

**Act sps**

p/2 (2a+(p-1)d) ------------------- = p^2/q^2 q/2 (2a+(q-1)d) 2a+pd-d ---------- = p/q 2a+qd-d q(2a+pd-d) = p(2a+qd-d) pqd + q(2a-d) = pqd + p(2a-d) (p-q)(2a-d) = 0 So, either p=q or d=2a

**maths**

First, you have to have the equation that relates chirp rate and temperature. Either you have been given that, or you can find it using google.

**Math probabilty**

looks good to me

**science**

all are matter compounds are formed of molecules molecules are formed of (usually different) atoms elements are formed of identical atoms

**math**

Let the ellipse be modeled by x^2/a^2 + y^2/b^2 = 1 Since the base has width 50, and the height is 28, we have b = 28 a = 25 and the ellipse is x^2/25^2 + y^2/28^2 = 1 When x=13, y=23.9

**Math hellppp**

correct. Although I'd have subtracted the beginning balance from the ending balance, showing that it had changed by $-77 (-12-65 = -77)during that month. But that was not one of the choices. D gives that answer, but the operations are bad.

**Math**

we have the piecewise cost function for weight w, c(w) = 2.50 for w <= 2 2.95 for 2 < x <= 3.5 3.40 for 3.5 < x <= 5 ... 2.50 + .45?(w-2)/1.5? So, now we want w such that 2.50 + .45?(w-2)/1.5? = 4.75 .45?(w-2)/1.5? = 2.25 ?(w-2)/1.5? = 5 4 < (w-2)/1.5 <= 5...

**Maths**

lim (x->1) (?(1+2x)-?(3x))/(?(3+x)-2?x) The fraction at x=1 is 0/0, so we have to try to resolve that. Multiplying by the conjugate of the denominator we have (?(1+2x)-?(3x))/(?(3+x)-2?x)) * (?(3+x)+2?x)/(?(3+x)+2?x) (?(1+2x)-?(3x))*(?(3+x)+2?x) / (3+x - 4x) as x->1 that...

**maths**

We have angle a in QII, and angle b in QI. So, sin a = 8/17 cos a = -15/17 sin b = 40/41 cos b = 9/41 sin(a+b) = sin a * cos b + cos a * sin b = (8/17)(9/41)+(-15/17)(40/41) = -528/697

**Math**

The distance fallen after t seconds is s(t) = 4.9t^2 meters So just plug in values for t. If you are interested in the distance fallen during the nth second, then just subtract the previous position. That distance d(t) is then just d(t) = s(t) - s(t-1)

**Math**

well, -6 is negative and |-8| is positive so, -6 < |-8| plot -5 and -8 on the number line. -5 is to the right of -8 so -5 > -8

**Language Arts need help fast!!**

all correct.

**Pakistan**

⌊ ⌋ ⌈ ⌉

**Pakistan**

⌊ ⌋

**Math**

If they used x gallons of 20% juice, then .20x + .70(20-x) = .40*20 x = 12 so, 12 of 20% and 8 of 70%

**ALGEBRA**

break-even is where cost = revenue. 43x+4576 = 65x ... P(x) = R(x)-C(x)

**ALGEBRA**

y=kx^2 y/x^2 is constant You want y such that y/11^2 = 3/9^2

**Math - eh?**

Ok. You have the polynomial 4x^3 - 12x^2 + 11x - 5 so what about it?

**Math**

correct

**Mathematics**

ar = 1 ar^4 = 8 Now divide and you get r^3 = 8 r = 2 so, a = 1/2 T8 = ar^7 = 2^6 = 64

**Math**

32/(8/2)+6=14

**pre-calculus**

A parabola has only one focus. You mean a hyperbola. Now, since the distances to the foci differ by 24, and the foci are 34 apart, you have a hyperbola with a = 12 c = 17 b = ?145 Since the center is at (-7,0) and the foci are on the line x = -7, the hyperbola is y^2/145 - (x+...

**science**

How long does it take to hit? h(t) = 45-4.9t^2 when is h=0? t = 3.03 seconds Now, what is h(2.03)?

**math**

Watch the amount of sugar and water: c(t) = (6+t)/(100+20t) Now you can answer the question.

**math**

x = ky^3/?z (x?z)/y^3 = k, a constant. So, you want x such that (x?4)/6^3 = (1372/3)(?9)/7^3 ...

**math**

If the width is w, then w(w+3)(w/7) = 242 ...

**ALGEBRA**

if the coefficients are real, then the complex roots occur in pairs. So, our polynomial is (x-2)(x-(4-3i))(x-(4+3i)) (x-2)((x-4)+3i)((x-4)-3i) (x-2)((x-4)^2+3^2) ...

**Maths**

?(x+?(x+?(x+...))) = 6 square both sides: x+?(x+?(x+?(x+...))) = 36 x = 36-?(x+?(x+?(x+...))) x = 36-6 = 30

**Math**

something wrong with my solution? Your question has not changed.*

**Math**

?((5+3)^2 + (-5-1)^2) = ?(8^2+6^2) = ?

**Maths**

1/4 + 3/6 = 3/4 So, 1/4 x = 2,50,000 (whatever that means...)

**math**

make that k2

**math**

r = k1v^2 + 2v^3

**Maths trigonometric**

8sinx-cosx = 4 8sinx = cosx+4 64sin^2x = cos^2x + 8cosx + 16 64-64cos^2x = cos^2x + 8cosx + 16 65cos^2x + 8cosx - 48 = 0 (5cosx-4)(13cosx+12) = 0 cosx = 4/5 or -12/13 so, sinx = 3/5 or 5/13

**algebra**

6^2 + h^2 = 12^2 so, what is h?

**Algebra**

14 hours = 50,400 seconds 855 minutes = 51,300 seconds yes, they are all about the same, but which is the smallest amount of time?

**Algebra**

I assume it means you need to multiply b^2 by something. Since b^8 = b^2 * b^6 b^6 goes into the box. Or, it might mean that b^2 is to be raised to a power. Since 8=2*4, (b^2)^4 = b^(2*4) = b^8 This appears to be just an exercise in working with properties of exponents.

**Maths**

I assume you mean log(384/5)+log(81/32)+3log(5/3)-log9 =log(384*81*125)/(5*32*27*9) =log(3888000/38880) =log 100 = 2

**Maths**

If you let u=3^x then the equation becomes (using parentheses to clarify matters) 9^(x+2) - 6*3^(x+1) = 0 9^2*9^x - 6*3*3^x = 0 81u^2-18u+1=0 (9u-1)^2 = 0 u = 1/9 So, 3^x = 1/9 = 3^-2 x = -2

**math**

Not even sure what the question is. If you are trying to write a fraction, then I'd guess at 9(4+2)/(3-1) = (9*6)/2 = 54/2 = 27 If that's wrong, then try rewriting it so we can tell what you want.

**Maths**

well, just plug in your numbers. (a) (1-h)^2 = 16 1-h = ±4 h = -3 or 5 Do (b) the same way.

**MATHS**

surely your text covers these topics. Offering complete courses is beyond the scope of this web site.

**Marh**

If there are x in the box, then 5/12 x = 3/8 x + 24 Multiply by 24 and you have 10x = 9x+576 x = 576

**pre algebra 1**

Assuming she only mowed the three lawns, then her total time was 1 3/4 + 2*(1 1/5) + 3/4 = 4 9/10 hours. That's 4:54, so subtracting that from 4:15, we have a start time of (using the 24-hour clock) 16:15 - 4:54 = 15:75 - 4:54 = 11:21 You are correct. Good job.

**Alegbra**

you should know that vertical angles are congruent. Each angle and its adjacent angle form a straight angle. So, the adjacent angles are 55°. 125+55 = 180 55+125 = 180 ...

**Math**

I think you're stuck. There's just no way to get things to just a product. According to wolframalpha, the integral is not elementary. http://www.wolframalpha.com/input/?i=integral+log(1-cotx)+dx