Wednesday

September 28, 2016
Total # Posts: 44,179

**Math**

time = distance/speed, so (400/(150/20)-400/(100/12.5))(100/12.5) = 26.66m

*September 21, 2016*

**Math**

(400/(150/20)-400/(100/12.5))(100/12.5) = 26.66m

*September 21, 2016*

**MATH**

after t hours, the amount left is 2 * (1/2)^(t/5)

*September 21, 2016*

**jay**

nope. And where are your divide symbols? P/2 = l+w now go from there.

*September 21, 2016*

**Calculus**

I assume you want k and m so that g(x) is continuous? Just to make things easier, recall that e^(ln u) = u so, e^(ln(2x+3)) = 2x+3 If so, then you want the endpoints to match: (k(-2)^2)+m = 2(-2)+3 k(3)-m = 2(3)+3 or, 4k+m = -1 3k-m = 9 I guess you can handle that, yeah? As ...

*September 21, 2016*

**math**

20-4-4-4-4-4 = 0

*September 21, 2016*

**Physics**

8.0 m/s^2 * 1km/1000m * (3600s/hr)^2 = 103680 km/hr^2 after h hours, the distances must be the same: 91.0h = 52.0h + 51840h^2 h = 0.000752315 hours = 2.7 seconds Or, you may want to convert km/hr to m/s, but the answer is the same. To get the distance, just plug it into either...

*September 21, 2016*

**math**

well, 2.5 = root(6.25) now just order the squares.

*September 21, 2016*

**Math**

2m^2+m-2m = 2m^2-m = m(2m-1) I suspect a typo, as this does not fit well with the grouping techniques.

*September 21, 2016*

**Math**

I get 4502 counted using bash: for i in `seq 1 11521` ; do echo $i ; done | tr -c -d '3' | wc -c

*September 21, 2016*

**biomechanics**

how long does it take for v to drop to zero? v(t) = 14.27 - 1.67t using that t, the distance moved is s(t) = 14.27t - 0.835t^2

*September 21, 2016*

**Physics**

or, more directly, recalling that the range is R = v^2/g sin2θ just solve for v in v^2/9.8 * sin62° = 8.3

*September 21, 2016*

**Math**

you manage to use + and x, but can't manage / ? 18+9x(5+4)/3-5 18+9x9/3-5 18+81/3-5 18+27-5 ... or 18+9x(5+4)/3-5 18+9x(9/3)-5 18+9x3-5 18+27-5 ...

*September 21, 2016*

**trigonomentry**

not sure what you mean by a "series" of cos, but if you recall your binomial expansions, (a+b)^4 = a^4+4a^3b+a^2b^2+4ab^3+b^4 and then let a=1 and b=cos^2(x), you have sin^8(x) = (sin^2(x))^4 = (1-cos^2(x))^4 = 1 - 4cos^2(x) + 6cos^4(x) - 4cos^6(x) + cos^8(x)

*September 21, 2016*

**Algebra**

well, to get rid of all those words, and use some math, 2u^4*v^2 / 3u = 2u^3v^2/3 or, 2/3 u^3v^2

*September 21, 2016*

**Math**

or, you can think of it like this 27 = 9*3, so 7:9 = 7*3 : 9*3 = 21:27

*September 21, 2016*

**physics**

You need to use the velocity, since distance = speed * time The speed is -15 m/s, so after t seconds, starting from x=30, x = 30 - 15t So, you are correct that x(1) = 15, but after 2 seconds, x(2) = 30 - 15*2 = 0 The object has indeed moved 30m after 2 seconds, but it has ...

*September 21, 2016*

**Geometry H**

E does not matter for this question. Since D bisects the angle, m<CBD = 1/2 m<CBA = 36

*September 21, 2016*

**physics**

you can make this hard (or more general) by setting up distance/speed calculations, and all that, but just notice that the river's speed is 1/2 that of the boat. So, the boat goes downstream 1/2 as far as it goes across.

*September 21, 2016*

**Math :)**

since 120° is 1/3 of a circle, the other two values must add up to 2/3, or twice the 120° value: x+8 = 2(x+2)

*September 21, 2016*

**java programming**

you better learn to read your java documentation. Here's a discussion of the topic: http://stackoverflow.com/questions/17538182/getting-keyboard-input

*September 21, 2016*

**Maths**

you can do it that way, but how has that helped? How do you solve x^2 = 3-2x ?

*September 21, 2016*

**GOVT JUNIOR COLEGE**

or, in the spirit of one "l", when your parot has gone.

*September 21, 2016*

**math**

google "polygon" and you will find many discussions. Or, check your course text. Or, just look in a dictionary!

*September 21, 2016*

**Math - check answer**

Looks good to me. But lots of time science folks like to use natural logs and base-e exponentials. So, since log 1.264911064 = .23500 1.264911064 = e^.23500 So, your function becomes f(t) = 58000 e^.235t

*September 21, 2016*

**physical sciences**

In one second he moves 15m, leaving 35m for braking. The speed decreases from 15m/s to 0 in 3 seconds, meaning the acceleration a = -15/3 = -5 m/s^2 Now, the distance traveled will be s(t) = 15t - 5/2 t^2 So, is s(3) less than 35m?

*September 21, 2016*

**Math**

10b + 3g + .5y = 100 b+g+y = 100 There's no unique solution, but you can see that g = 20 - 19b/5 y = 80 + 14b/5 So, it is clear that b must be a multiple of 5. Now, if b=5, g = 20-19b/5 = 20-19 = 1 So, 5 blue, 1 green and 94 yellows works out fine. You can't have more ...

*September 21, 2016*

**Maths**

x + 2(2x-4) = 57

*September 21, 2016*

**Math**

oh, you can complicate it up a bit by using a proportion: x/3 = 4/1 but this one is in fact pretty simple.

*September 21, 2016*

**Math**

if the ratio is 4, then the similar figure has lengths 4 times as big as the original. 4*3 = 12

*September 21, 2016*

**8th grade math-exponents**

it's a lot easier without all those words: (x/2)^3 * (x/2)^4 ---------------------- ((x/2)^3)^2 = (x/2)^7 / (x/2)^6 = x/2 Hmmm. Not what you want. I suspect a typo somewhere.

*September 21, 2016*

**Math**

aha! That means that while sinx=4 is a "solution" to the polynomial, it is not a real solution. It is extraneous, due to the properties of sin(x)

*September 21, 2016*

**Math**

quadratics always work. Maybe it just doesn't factor easily. Nope. works just fine: (3sinx+1)(sinx-4) = 0 Now just evaluate sinx so you get solutions for x.

*September 21, 2016*

**Differential equations**

you can start by noting that if u = ln(5x/(x+3)) du/dx = 3/(x^2+3x) The rest should be not so hard now.

*September 21, 2016*

**Math**

can you say run-on sentence? Slow down and say what you want - that breathless jumble is giving me a headache!

*September 21, 2016*

**math**

First step: come up with a function you want to minimize. Can you describe the cost in terms of the quantities?

*September 21, 2016*

**Math**

Hmmm. Better go with Reiny. I thought my answer was a bit odd.

*September 21, 2016*

**Math**

15/2 √279

*September 21, 2016*

**Math**

If the change in longitude is θ radians, the WE distance is 6400θ km. Since time = distance/speed, then (assuming a constant speed), (6400θ + 4500)/950 = 11 θ = 0.9297 = 53.3° So, now you know how far East Q is from P. As for QR, 4500 = 6400θ so, ...

*September 21, 2016*

**Algebra 1**

It is used for exponents, but some rather strange people use it to mean ^2 or squared. Going on that assumption, we have 3[42-2 (10^2-9^2)] 3[42-2(100-81)] 3[42-2*19] ... If I got that wrong, TJ, fix it and carry on.

*September 21, 2016*

**College Algebra**

1/x + 1/(20-x) = 4/15

*September 20, 2016*

**Math**

use the usual distance formula: √(((a-3b)-(a+4b))^2 + (a-(a-b))^2) = √(-7b)^2+(b)^2) = √(50b^2) = 5b√2

*September 20, 2016*

**PreCalculus**

sorry about the time. I had to guess at the unasked question.

*September 20, 2016*

**PreCalculus**

it is 10:24 a.m.

*September 20, 2016*

**Math**

looks good to me

*September 20, 2016*

**Math**

well, how many ounces in 6 lbs? Divide that by 5oz/apple to get the no. of apples.

*September 20, 2016*

**6th Grade Maths**

45/(2 x 4.7 - 4.4) x 6 = 54

*September 20, 2016*

**Advanced Functions 12**

not sure what the secant lines mean. At x = 1/2, they all pass through 1/2 f(x) = (3 - 1/4)/2 = (1/2,11/8) That won't get anywhere near the tangent line, no matter what other point you choose. I suspect there is something left unsaid here.

*September 20, 2016*

**Math**

well, the list of running times is 5,7,8 can you not figure the range of such a list?

*September 20, 2016*

**calculus need help**

Really. Ha you know that the solution of y" + y = 0 is y = a sinx + b cosx Now use the method of variation of parameters: We now have y1 = sinx y2 = cosx The Wronskian of {sinx,cosx} is -1 u1 = ∫cosx tanx dx = ∫sinx = -cosx u2 = -∫sinx tanx dx = ∫...

*September 20, 2016*

**math**

cannot access files stored on your computer. duh.

*September 20, 2016*

**Math**

(1/3 ft)/ (1/6 yd) but, since 1 yd = 3 ft, you have = (1/3 ft) / (1/2 ft) = (1/3) / (1/2) = 2/3

*September 20, 2016*

**maths**

You have three unknowns, and only two equations. Here is what wolframalpha.com says: c+s+h = 100 5c + s/10 + 2h = 100 http://www.wolframalpha.com/input/?i=solve+c%2Bs%2Bh+%3D+100,+5c+%2B+s%2F10+%2B+2h+%3D+100 There is no unique solution, but if you play around, you can see ...

*September 20, 2016*

**algebra**

correct

*September 20, 2016*

**algebra**

what do you mean by "write a full" ? Note that as x grows by 1, y grows by 2. SO, start wity y = 2x Now adjust that so that the values agree with those in the table.

*September 20, 2016*

**Math**

5.25/.75 = ?

*September 20, 2016*

**Math**

Why have two variables? Each function has a flat fee and an hourly rate. The only variable is the time. You want the time to be such that the two cost are equal. Where did you get the 2? You're not multiplying by the number of service calls. Each service call has a flat ...

*September 20, 2016*

**Math**

well, st = u + v/2 now just one more step to go...

*September 20, 2016*

**math**

again? See your first post, or the related questions below

*September 20, 2016*

**Math**

if moving in the same direction as the bus, just add the speeds. If moving in the opposite direction, subtract her walking speed from the bus's speed.

*September 20, 2016*

**Math**

No. It grows 144/7 = 20.57 inches. Think about it. It takes 7 days to grow 6 inches. 24 is a little more than 3*7. So, it will grow a little more than 3*6 = 18 inches. You need to work on your reading, too...

*September 20, 2016*

**Math**

If it were 21 days, since 21 = 7*3, it would grow 6*3 = 18 inches. 24 is not quite that simple. It grows (24/7) * 6 = 144/7 inches why did you multiply 6 by 4? You cannot multiply days by inches. The units make no sense. Instead, you want to convert days to inches, using the ...

*September 20, 2016*

**math**

see earlier post

*September 20, 2016*

**Math**

draw the vectors. Since they are perpendicular, the resultant is just the hypotenuse of the triangle.

*September 20, 2016*

**Jewelry**

Seems like I read about this necklace in a mystery novel...

*September 20, 2016*

**math**

solve as you would an equation. The only thing to watch for is to change the direction of the inequality when multiplying by a negative quantity. 2(3x−6)>=5x-10 6x - 12 >= 5x-10 6x-5x >= -10+12 x >= 2 So, pick out all the values at least 2. To be sure, ...

*September 20, 2016*

**math**

you ask us to show our work in solving the problem. Why not show your work and how it went wrong? I suspect a typo, since 5(0) - 10 = -5 That makes your equation 2(3x-6) = -5 So, does -5 work? 2(3(-5)-6) = 2(-15-6) = 2(-21) = -42 Nope. Now you try the others to see whether any...

*September 20, 2016*

**Math**

fifty seven million three hundred seventy-three thousand two hundred eighty-four = 57373284 Now just move the decimal place as needed.

*September 20, 2016*

**Algerbra**

well, 1.7x10^2 = 0.17x10^3 Now just add 'em up

*September 20, 2016*

**Math**

review the conditions for the series to exist. In this case, it will exist for x=0, so we want y = ∑anx^n y' = ∑nanx^(n-1) y" = ∑n(n-1)anx^(n-2) The DE then says ∑n(n-1)anx^(n-2) + x*∑nanx^(n-1) + ∑anx^n = 0 ∑n(n-1)anx^(n-2...

*September 20, 2016*

**math - eh?**

You want to try that again in English?

*September 20, 2016*

**Math Question**

why are there 4 empty squares? Or are some of the numbers used more than once?

*September 20, 2016*

**maths**

c+s+h = 100 5c + s/10 + 2h = 100 There is no unique solution if that is all you are given. And the plural of sheep is sheep, not sheeps, and certainly not sheep's!

*September 20, 2016*

**Math**

just multiply 5 by the desired value(s)

*September 20, 2016*

**physics**

no friction means no force no force means no acceleration no acceleration means constant velocity.

*September 20, 2016*

**maths calculus need help plz**

this is a pretty standard linear DE. Read about its method of solution here: https://answers.yahoo.com/question/index?qid=20120112065721AA0UzfI If you're still confused, there are lots of explanations on why the method works so well.

*September 20, 2016*

**Math**

recall that the angles of a triangle sum to 180°. So, you must have 2x+5 + 6x-5 + 7x = 180

*September 20, 2016*

**ALGEBRA**

(212-32) = 180 SO, there are 180°F for 100°C So each °F is 5/9 as big as a °C each °C is 9/5 as big as a °F That should help you get started.

*September 20, 2016*

**Math**

really? How many times larger is 20 than 4? How did you get that answer? Do the same thing for your numbers. Remember that you divide the values and subtract the powers. What do you get?

*September 20, 2016*

**Matg**

Luckily, the 3' width of the rolls divides either dimension of the room, so you don't have to worry about buying extra rolls for the leftover width. Carpet Master: (720*30 ft^2) * 1roll/6ft^2 * $1/roll = (720*30*1/6*1) = $3600 Flooring King: (720*30 ft^2) * 1roll/36ft^...

*September 20, 2016*

**physics**

oops: watch the units (66.4km/hr) / (t hr) = 66.4/t km/hr^2 I'd say: total distance: 99.5(t - 24/60) avg speed = distance/time 99.5(t - 24/60)/t = 66.4 t = 1.202 distance is thus 99.5(1.202 - 24/60) = 79.8 km

*September 20, 2016*

**Maths Constructions**

you can construct a right angle by making a perpendicular bisector of a line segment. That's one of the very first constructions you did. Mark the right angle as point B. Then, mark off side BA. Then from A, set the radius to 6.2cm and draw an arc that intersects the ...

*September 20, 2016*

**Math**

Let C = {4,5} Then A = {2,C,4} They are all incorrect, and it should be clear why. What are your reasons?

*September 20, 2016*

**Algebra**

since distance = speed * time, (s-50)(5) = (s+50)(4.5) That's some fast plane!

*September 20, 2016*

**Precalculus**

For the inside argument, the domain is all real numbers except where the denominator is zero. If your denominator is -x^2-4x-10 it is never zero, since the discriminant is 16-40 < 0 So, the domain is (-∞,∞) Now, for the log to be defined, we need 10+|x+6|/(-x^2-...

*September 20, 2016*

**Algebra**

g = b+16 g+13 = 2(b+13) now just solve for g and b.

*September 20, 2016*

**math**

no, 2+2 = 4

*September 20, 2016*

**science**

Since PV=kT, PV/T is constant. So, you want T where (1.41)(25.1)/T = (1.82)(18.7)/353

*September 19, 2016*

**Calculus**

yes, k=2

*September 19, 2016*

**Pre algebra**

-12/(3(-8+(-4)^2-6)+2) -12/(3(-8+16-6)+2) -12/(3(2)+2) -12/8 -3/2

*September 19, 2016*

**Math**

Do you mean 8*4^(2x) - 4 = 53 8*4^(2x-4) = 53 either way, isolate the 4^? and then take log of both sides to get x by itself on the left.

*September 19, 2016*

**math**

a. The power of an electric appliance is given by the formula P=I^2R, where I is the current and R is resistance. Use this information to explain how you can use radicals to determine the current if the power and the resistance is given. b. Find the current in amperes if a 40-...

*September 19, 2016*

**MATH**

can't see, but I'd bet that it's √2 times the value shown.

*September 19, 2016*

**Math please help**

It does not matter! Pick any number you like. Just be sure to use it both top and bottom. I know you have trouble with math, but I was hoping you could understand English...

*September 19, 2016*

**Math please help**

starting with 5/6, multiply both top and bottom by the same number, such as 3: 5/6 = 15/18 Now fill in the other blanks.

*September 19, 2016*

**Grade 10 Math**

As always, draw a diagram. She is standing 3 ft from where the wire is attached to the ground. Using similar triangles (in inches), the height h can be found by 69/36 = h/180

*September 19, 2016*

**Algebra**

Ab^2 = -18 A(3^(1/5))^2 = -18 A(3(2/5)) = -18 A = -18 * 3^(-2/5) = 18 / 9^(1/5) = 2 * 9^(4/5) It would be nice if you showed your work ...

*September 19, 2016*

**Algebra**

Ab^-3 = -6 Ab^2 = -18 divide to get rid of the A's and you have b^-5 = 1/3 b^5 = 3 b = 3^(1/5) Now use that to get A

*September 19, 2016*