Thursday

January 19, 2017
Total # Posts: 47,946

**Calculus**

when the water has depth y, the surface has with 4/3 y. That means the volume is v = y(4/3 y)/2 * 15 = 10y^2 dv/dt = 20y dy/dt Now just plug in your numbers to find dy/dt

*December 10, 2016*

**Algebra**

This is a trick question. |u| is always positive, so |1-4k| ? -11 for any value of k. Damon's solution is correct, but it should read k >= -2.5 OR k <= 3 So, any value of k will work.

*December 10, 2016*

**Math**

profit = revenue - cost revenue = price * demand P(x) = x(200-0.5x) - (100+5x+7x^2) = -7.5x^2 + 195x - 100 Now just find the vertex of that parabola.

*December 10, 2016*

**maths probability**

I hope he had fun.

*December 10, 2016*

**Math**

well, why do you not simply use the formula? i = P((1+r/n)^(nt)-1) and plug in your values?

*December 10, 2016*

**Math**

m/n= (m+b)/(n+b) m(n+b) = n(m+b) mn+mb = mn+nb b(m-n)=0 b=0 or m=n The question is poorly explained. It clearly said Does there exist a fraction(s) m/n... so offering a single example would indeed answer the question!

*December 10, 2016*

**Geometry**

15-9 < x < 15+9 so (C) is correct. If it were 24, then the triangle would collapse to just a line.

*December 10, 2016*

**Math**

4?/3 r^3 = 15000 r^3 = 45000/(4?) r = 10?(45/4?) or 5?(90/?)

*December 10, 2016*

**math**

area has the ratios squared, so 2^2:3^2 = 4:9

*December 10, 2016*

**Math.**

also 2:3

*December 10, 2016*

**math check my answer please**

Just as ?125 = 5?5, ?b^3 = b?b You went a bit astray, so we should have 3?(125a^1b^3) = 3*5b?(5ab) = 15b?(5ab) The 3 does not distribute across products. The distributive property only applies to addition, as in 3(?a + ?b) = 3?a + 3?b

*December 9, 2016*

**soil mechanic**

um ?

*December 9, 2016*

**math help**

?(48ab^2) = ?48 * ?a * ?b^2 = ?16 * ?3 * ?a * b = 4b?(3a)

*December 9, 2016*

**Math**

sorry. You have the equation. Plug in the given x or y value and solve for e or f. You gotta do something here, dontcha? Stop looking for freebies...

*December 9, 2016*

**Math**

Assume a straight line. As x increases by 2 (5-7) y increases by 6 (13-19). So try y = 3x But, 13 - 3*5-2. So, try y = 3x-2 it works for all the known pairs. So, fill in e and f.

*December 9, 2016*

**Math**

correct.

*December 9, 2016*

**Math**

Nope. The slopes are 1 and -1, so their product is -1. That means they are perpendicular.

*December 9, 2016*

**geometry**

google is your friend. Try this: https://www.algebra.com/algebra/homework/word/geometry/Angle-bisectors-in-an-isosceles-triangle.lesson

*December 9, 2016*

**Geometry**

ABE+ABC = 180, so ABC = 180-ABE ABC = (180-y)/2 so, 180-(3x+20) = (180-y)/2 160-3x = 90 - y/2 70-3x = -y/2 y = 6x-140

*December 9, 2016*

**math**

no, m+5m = 6m cm area is m*5m = 5m^2 cm^2

*December 9, 2016*

**math**

I don't know what you mean by "solve" it. It's just an expression. No equation. (0.08b^{4m+8})/(18b^{m?2}) = .08/18 b^(4m+8-(m-2)) = 1/225 b^(3m+10) 1/(1/5) m^(4-n) * 1/2 m^(n-6) = 5/(2m^2)

*December 9, 2016*

**Calculus**

and ... ?

*December 9, 2016*

**Algebra**

Draw the line. It lies in QII, QI, QIV

*December 9, 2016*

**precalculus**

divide by -2 ant it changes to r = -2/(1+3sin?) now what do you think?

*December 9, 2016*

**precalculus**

since tan?/sec? = sin?, can you handle r sin? = 2 ??

*December 9, 2016*

**Algebra 1**

yep.

*December 9, 2016*

**precalculus**

the standard equation is r = ep/(1 - e sin?) so, if you divide top and bottom by -2 you get r = -2/(1+3sin?)

*December 9, 2016*

**precalculus**

tan?/sec? = sin? so, can you convert r sin? = 2 ??

*December 9, 2016*

**math**

if the cuboid has sides x,y,z, then the main diagonal d has length d^2 = x^2+y^2+z^2

*December 9, 2016*

**math**

That is really a=p(1+r/n)^(nt) Assuming you mean compounded quarterly, just plug in your numbers, with r=0.043 n=4 t=6

*December 9, 2016*

**Math**

f+t = 26 5f+10t = 210

*December 9, 2016*

**Algebra**

well, that would be 2/9 * 2493, right?

*December 9, 2016*

**Quadratic Relations, Algebra, Math**

solve for h = 0.5 -4.9t^2+14t+2.5 = 0.5 now just use the quadratic formula.

*December 8, 2016*

**math**

Cause the exponent is positive you move the decimal point 3 places to the right so that would = 1900

*December 8, 2016*

**Algebra**

12.50-8.75=3.75 You have $3.75 left for toppings $1.25*3=3.75 You can have 3 toppings

*December 8, 2016*

**algebra**

P = kmT/V (usually written as PV = knRT) Anyway, that means that PV/Tm = k a constant So, you want P such that 180P/(3*280) = (1170*720)/(6*260)

*December 8, 2016*

**MATH MS. SUE**

See you tomorrow Ms. Sue I have to go to bed but Ill have those explanations up soon

*December 8, 2016*

**MATH MS. SUE**

Yeah, just unsure on 2, and 3

*December 8, 2016*

**MATH MS. SUE**

Do you want me to give you an explanation for them?

*December 8, 2016*

**MATH MS. SUE**

I did the math silly

*December 8, 2016*

**MATH MS. SUE**

Are those correct?

*December 8, 2016*

**MATH MS. SUE**

1. B 2. C 3. A 4. A

*December 8, 2016*

**MATH MS. SUE**

Alright I don't have any answers in mind but I'd like your help hand me some equations to solve for this

*December 8, 2016*

**MATH MS. SUE**

Spare me a second please, Ms. Sue

*December 8, 2016*

**MATH MS. SUE**

1. The length of a piece of paper is 8.5 inches. Using scissors, you reduce the length of the paper to 4.25 inches. What is the scale factor of the dilation? A. 1/4 B. 1/2 C. 2 D. 4 2. On a given blueprint, 1 inch = 30 feet. If the dimensions of a meeting room on the blueprint...

*December 8, 2016*

**Diagram**

Racist: Please stop bill

*December 8, 2016*

**Diagram**

This is a repost from a few weeks ago from someone esle but need help. The ramp shown below is used to move crates of oranges to loading docks at different heights. When the horizontal distance AB is 15ft, the height of the loading dock, BC, is 3ft. What is the height of the ...

*December 8, 2016*

**MATH**

2. 3^2 = 9 9*13 = 117 Am I right?

*December 8, 2016*

**MATH**

1. = 10*6 = 60

*December 8, 2016*

**MS. SUE HIIII**

Equation

*December 8, 2016*

**MATH**

1. The sides of a square are increased by a scale factor of 6. The perimeter of the smaller square is 10 ft. What is the perimeter of the larger square? A.10 ft B. 40 ft C. 60 ft D. 120 ft 2. A right triangle has an area of 13 m^2. The dimensions of the triangle are increased ...

*December 8, 2016*

**MATH MS. SUE**

Yes you were very much help and I thank you for that

*December 8, 2016*

**MATH MS. SUE**

B. $144.04

*December 8, 2016*

**MATH MS. SUE**

OK thank you but you didn't help it is divide 157/1.09 = 144.0366...

*December 8, 2016*

**MATH MS. SUE**

1. On a recent day, one U.S. dollar was worth 1.09 euros. If you were to exchange 157 euros on that day, how many U.S. dollars would you have received? A. $110.09 B. $144.04 C. $155.91 D. $171.13

*December 8, 2016*

**Math**

all real numbers except where t^2+6t+9 = 0

*December 8, 2016*

**MATH MS. SUE**

x = 49/10 Thanks Ms.Sue

*December 8, 2016*

**MATH MS. SUE**

Hand me over an equation please.

*December 8, 2016*

**MATH MS. SUE**

1. Sarah’s mother has a miniature village modeled after her home town. The model is 10 feet long and 7 feet wide. The actual village is 7 miles long. What is the village’s actual width? If necessary, round to the nearest tenth of a mile. A. 4.9 miles B. 10 miles C. 1...

*December 8, 2016*

**Math**

it would help if you actually provided a sequence... As long as no x value maps to two or more y values, it is a function.

*December 8, 2016*

**Math**

a depth of 4 feet means you need ? [-10,-6]

*December 8, 2016*

**math**

Just add up the revenue from each kind of ticket. The total must be 779: 3s+5t = 779

*December 8, 2016*

**Math**

8×5+8×1 -2×6+6-2 = 22 hint: 48-26 = 22

*December 8, 2016*

**Math**

122.5 sips * 2slurps/7sips * 2gulps/5slurps = ? gulps The units cancel as desired, so just work with the numbers.

*December 8, 2016*

**Algebra**

at time t hours, since distance = time * speed, when they have covered the 26 miles, solve for t. 6t + 8(t-1.3) = 26

*December 8, 2016*

**Math**

This web site shows how to find the area of the cross-section. Using that, the volume is 40*area. The weight is density * volume. Then you can either integrate to find the work, or just see how high the center of mass has to be lifted, and work = weight * distance. http://...

*December 8, 2016*

**math**

when 625-300t = 400-150t

*December 8, 2016*

**Math - Calculus**

okay. You seem to be using shells, so you need to be integrating along y, since the shells have a thickness of dy. v = ?[0,6] 2?rh dy where r = y and h = 4-x = 4-y^2/9 v = ?[0,6] 2?y(4-y^2/9) dy = 72? If you want to integrate along x, you need to use discs of thickness dx: v...

*December 8, 2016*

**Trig identities**

well, that does make a difference. You just need to think about what happens in the various quadrants. Recall that sin? = y/r cos? = x/r r is always positive, so if sinx is positive, and cosy is negative, that means you are in QII. Now you know that sinx = 3/5 cosx = -4/5 siny...

*December 8, 2016*

**Math (optimization) really confused**

As always, in similar problems, the fence is evenly divided into lengths and widths. So, you know right off that 2y=3x. y(2y/3) = 225 y^2 = 675/2 y = 18.37 x = 12.23

*December 8, 2016*

**Math**

64 oz = $2.00 divide by 64 to get 1oz = $2/64

*December 8, 2016*

**Math**

clearly not D. Using that, p(15) = 60+16 = 75, when the projection states it will be 450 We have a slope (4) and a point (15,450). So, using the point-slope form, we get p-450 = 4(x-15)

*December 8, 2016*

**Trigonometric identities**

well, you know that sinx = 3/5 cosx = 4/5 siny = 12/13 cosy = 5/13 Now just use the identity sin(x-y) = sinx cosy - cosx siny

*December 8, 2016*

**MATH**

a = 75x b = 50x for x <= 12 50*12+125(x-12) for x > 12

*December 8, 2016*

**h.p.**

Tn = (2n-1)(2n+1) = 4n^2-1 so n ?Tk = ?4k^2-1 = 4?k^2 - 4?1 k=1 Now you know what ?k^2 is and ?1 = n

*December 8, 2016*

**science**

it lost 20m/s in 25 seconds. So, each second it lost 20/25=0.8 m/s a = -0.8 m/s^2

*December 8, 2016*

**g.p. - homework dump**

geez - you ever going to show some of your own work? These slow-mo homework dumps are annoying.

*December 8, 2016*

**Math (related rates) help?**

yes - so, try it sin? = y/13 cos? d?/dt = 1/13 dy/dt Now just plug in your numbers. Use the Pythagorean Theorem to figure cos? when y=12.

*December 8, 2016*

**math**

1.10(568+102-57) = ?

*December 8, 2016*

**math**

B the two lines have different slopes, so they must intersect.

*December 8, 2016*

**h.p.**

so, if you have the answer, what are your thoughts on how to get it?

*December 8, 2016*

**Maths**

Remember your basic 3-4-5 right triangle. Scale it up by 3 and you have 9-12-15. Now draw your diagram, and all should be clear.

*December 8, 2016*

**Math**

you don't say at what point the wheel starts. Let's say that at t=0 the point of interest at the bottom of the rotation. Since cos(t) starts at the top, we know right away that the function will look like y = -cos(kt) The diameter is 18, so the radius is 9, and we now ...

*December 8, 2016*

**MATH**

The three vectors form a triangle. So, recall the law of cosines. c^2 = a^2 + b^2 - 2ab cos?

*December 8, 2016*

**Solving inequality Test 29 questions**

You don't offer many choices...

*December 8, 2016*

**Maths**

After 10 days, there was enough food for 20 days for x students. So, if the number of students grew from x to x+60, it will only last 20x/(x+60) = 20 - 1200/x+60 more days. So, it depends on how many students there were to start with. If there were x at first, then the 20-day ...

*December 8, 2016*

**calculus**

Check the graph. Is f'(x)=0 anywhere on the interval? Clearly not, so now you have to figure out why. Is f(-1) = f(1)? Is df/dx defined everywhere on the interval? (check out x=0)

*December 8, 2016*

**Electrical Circuits**

well, what is copper's thermal resistance coefficient?

*December 8, 2016*

**maths**

check out the angles and distances.

*December 8, 2016*

**Math**

well, it took 1/2 hour, so ...

*December 8, 2016*

**Algebra II**

If the square has side s, then 4s = 2(x+4 + x) s^2 + x(x+4) = 94 ...

*December 8, 2016*

**geometry**

no idea. How are the angles related? What is the diagram being discussed?

*December 8, 2016*

**G.p.**

a = 1 r = 1/2 S12 = (1 - 1/2^12)/(1 - 1/2)

*December 8, 2016*

**G.p.**

b-a = c-b 1/a^2 - 1/b^2 = 1/b^2 - 1/c^2

*December 8, 2016*

**Math**

well, add 'em up: 2 4/8 3 3/8 1 2/8 ------- 6 9/8 = 7 1/8

*December 7, 2016*

**math**

(450-45)/450 = ? Or, you can reason that 45 is 10% of 450 that were used, so ...

*December 7, 2016*

**Trigonometry**

24.91 @ S36°W

*December 7, 2016*

**MATH, please help**

they are in proportion because 8*9 = 6*12 In a proportion a/b = c/d ad = bc

*December 7, 2016*

**Math**

12% is about 1/8 so, you need about 8 times the amount.

*December 7, 2016*