Saturday

August 27, 2016
Total # Posts: 42,820

**Math**

see related questions below
*August 23, 2016*

**Math**

(5600*.95)*1.10 = .95p
*August 23, 2016*

**math**

6 = 2*3 so, 3 times as far as he went in 2 hours.
*August 23, 2016*

**maths**

since cos(a+b) = 0, a+b = pi/2 so, b = pi/2 - a and sin(a-b) = sin(a-pi/2+a) = sin(2a-pi/2) = -sin(pi/2 - 2a) = -cos(2a) or, since a = pi/2 - b = -cos(2(pi/2-b)) = -cos(pi-2b) = cos(2b)
*August 23, 2016*

**Geometry**

just use the distance formula for each segment.
*August 23, 2016*

**Math**

if the first vertex is at (1,0), then the others are at (cos 2kπ/7, sin 2kπ/7) for k=1..6
*August 23, 2016*

**Math**

$5.50 no matter how many hours. Now, if you want an hourly rate, well, duh -- divide the money by the time: $/hr
*August 23, 2016*

**physics**

series: R = 6 parallel: R = 1/6 Other arrangements will produce values in between those.
*August 23, 2016*

**Maths**

well, with those two roots, f(x) = (x+2)(x-3) so expand that and you can see what p and q must be.
*August 23, 2016*

**Math**

5 is 3 * 5/3 So, the distance is (5/3)(189)
*August 23, 2016*

**algebra**

google your question. Much faster than waiting around here: https://www.google.com/#q=metric+ton
*August 23, 2016*

**Urgent help! Physics**

Vx = v cosθ Vy = v sinθ h(t) = Vy*t - 5t^2 ball stops when h=0 ball has traveled Vx * t along the ground.
*August 23, 2016*

**Algebra**

n = 6+4 "exceeds" and "more than" indicate addition. See what you can do with q.
*August 23, 2016*

**Math**

2/5 + 1/5 + 1/x = 1 x = 5/2
*August 23, 2016*

**Math**

Just list the possibilities. You know there are 36 total outcomes. How many fit the conditions? R B R-B 1 1 0 1 2 -1 1 3 -2 2 1 1 2 2 0 2 3 -1 2 4 -2 ... 4 6 -2 Then divide the successes by the total of 36
*August 23, 2016*

**Math**

so, she picked 2*35 + 15
*August 22, 2016*

**maths**

If there are x liters of 25/L then we have the value of the milk as 25x + 30(60-x) = 1600
*August 22, 2016*

**math**

distance = speed * time, so (1/2 hr) * (y mi/hr) = y/2 mi
*August 22, 2016*

**Math**

4/(5+4+y)
*August 22, 2016*

**phy**

the waves are a sin(x) and b sin(x-k) add them up and you have a sinx + b(sinx cosk - cosx sink) = (a+b*cosk)sinx - (b*sink)cosx This is basically just Asinx + Bcosx which can be reduced to a single sine wave of amplitude √(A^2+B^2) See a nice discussion at https://en....
*August 22, 2016*

**pre caluclus**

since you give only one focus, I assume it's a parabola. Since both points lie on the line y=2, the parabola opens horizontally. Recall that y^2 = 4px has focus at (p,0) and vertex at (0,0) Your parabola has obviously been shifted up by 2, so it will be (y-2)^2 = 4px Your ...
*August 22, 2016*

**Math**

just recall that supplementary angles add to 180, so 4x+3 + 3x-5 = 180 Now just solve that for x.
*August 22, 2016*

**Algebra 1**

the first step is usually to clear all the fractions by using the LCD. In this case 12. Do that and you have z/3 - 3 = z/4 + 7 4z - 36 = 3z + 84 z = 120 Or, you can collect terms as usual, and then clear fractions z/3 - 3 = z/4 + 7 z/3 - z/4 = 10 (1/3 - 1/4)z = 10 1/12 z = 10 ...
*August 22, 2016*

**algebra**

These are all difference of squares or sum/difference of cubes. You need to be able to recognize such values, and apply the formulas: a^2-b^2 = (a-b)(a+b) a^3±b^3 = (a±b)(a^2∓ab+b^2) For example, 16x^4a-y^8a = a(16x^4-y^8) = a(4x^2+y^4)(4x^2-y^4) = a(4x^2+y...
*August 22, 2016*

**Algebra**

since V is proportional to r^3, V(2r)/V(r) = 2^3 gather all the constants into a single k, and you have V(r) = kr^3 V(2r) = k(2r)^3 = k(2^3)(r^3) = 2^3*V(r)
*August 22, 2016*

**math**

one every polynomial of degree n has exactly n solutions.
*August 22, 2016*

**Algebra 1a**

no kidding. In big letters on the home screen it says Post homework questions online a general whine is not a homework problem.
*August 22, 2016*

**Math**

2450 - 2549 but I must say I do not care for the way the question was worded.
*August 22, 2016*

**Algebra**

√(3x-6) = 4 3x-6 = 4^2 = 16 3x = 22 x = 22/3
*August 22, 2016*

**Algebra**

3c^2 - 5c - 7.8 = -2.2 3c^2 - 5c - 5.6 = 0 Now just use the quadratic formula
*August 22, 2016*

**Math**

correct
*August 22, 2016*

**Algebra**

well, you know that y = 3.8x+2.2 so use that in the other equation to get 4.5x - 6.7(3.8x+2.2) = 8.6 4.6x - 25.46x - 14.74 = 8.6 now it's easy, right? Then, once you have x, use that to get y.
*August 22, 2016*

**Math**

1st step: subtract 5.514 from both sides: 9.2x = 152.72 I guess you can figure out what's next, no?
*August 22, 2016*

**Algebra**

65.9 - 32.4k/9.9 = 13.3k 65.9 - 3.28k = 13.3k Think you can handle that now?
*August 22, 2016*

**Absolute Value**

all correct.
*August 22, 2016*

**Algebra**

why all the words? You showed the math. Just solve the way you normally would; don''t let the fractions confuse things. 1/2.75 = 1/3.2 - 1/x 1/x = 1/3.2 - 1/2.75 1/x = (2.75-3.2)/(3.2*2.75) x = (3.2*2.75)/(2.75-3.2) = 8.8/-0.45 = -19.556 Or, just convert to decimals at...
*August 22, 2016*

**math**

sheet area: 32*24 buttons area: 64 * π * 3.5^2 now just subtract
*August 22, 2016*

**algebra 1 please help**

just plug in your numbers: (81+125)/2 * 75
*August 22, 2016*

**MATHS (EQUATIONS)**

.8x + .9y = 240
*August 22, 2016*

**Maths**

ooops. Misplaced the decimal point. I'm sure you can fix it.
*August 22, 2016*

**Maths**

juice: 9% of 120L = .09*120 = 1.08L And so on
*August 22, 2016*

**Maths**

it's a line: http://www.wolframalpha.com/input/?i=-3x%2B2y%3D-6
*August 22, 2016*

**American Government**

nope - that's what the Supreme Court decides
*August 22, 2016*

**math**

well, 36000000 * 6 = 600^3
*August 22, 2016*

**Math**

same answer using the exterior angles, which sum to 360°
*August 22, 2016*

**science**

straight lines have a constant slope. That is often written y = kx In this case, the quantities have different names, but it should be clear which choice is correct if you just use your names instead.
*August 22, 2016*

**science**

hint: it's called a half-life for a reason.
*August 22, 2016*

**algebra**

i = kpt, so if p is the same, i/t = pk is constant. Thus, you want i such that 960/6 = i/7 That is, since 7 is 7/6 as big as 6, the interest will be 7/6 * 960
*August 22, 2016*

**math**

If the cardboard is x by y, then xy = 160 2(x-4)(y-4) = 144 Now just solve for x and y.
*August 22, 2016*

**ALGEBRA**

time = distance/speed, so if he rode x miles on the bike, x/43 + (281-x)/3 = 7 solve for x, and then x/43 is the time on the bike.
*August 22, 2016*

**maths**

If the number is x, then x = 10t+5 so, 10t+5 = 7(mod 11) 10t = 2(mod 11) so, which multiple of 10 leaves a remainder of 2 when divided by 11? How about 90 = 88+2? So, t=9 95 = 10*9+5 = 11*8+7
*August 22, 2016*

**Math 2**

That's phi, not phe Ø-1 = 1/Ø Ø^2-Ø-1 = 0 Ø = (1±√5)/2 pick the positive value
*August 21, 2016*

**physics**

time = distance/speed( m / m/s = s) avg velocity is totaldistance/totaltime so, that gives (95.0+95.0)/(95.0/1.26 + 95.0/3.61)
*August 21, 2016*

**Calculus**

you know that sin(x) is negative in QIII and QIV sin(.294) = 0.29 so, you want the numbers π+.294 and 2π-.294
*August 21, 2016*

**Calculus**

You know that lim sinu/u = 1, so sin2x/5x = sin2x/2x * 2/5
*August 21, 2016*

**Algebra**

If you meant |t| -2 = -1 |t| = 1 then B
*August 21, 2016*

**Maths Mensuration**

2π*3 * 14
*August 21, 2016*

**Maths Mensuration**

A(r) = πr^2 A(r+h) = π(r+h)^2 now subtract.
*August 21, 2016*

**Mathematics**

then f(0) = -1 But then, that may not be what you were after ... Hard to say, since you did not. But it does factor easily, right? It's just Algebra I
*August 21, 2016*

**chemistry**

So, first step: decide on the partial equations. There's a good discussion here: http://chem-guide.blogspot.com/2010/03/balancing-chemical-equations.html
*August 21, 2016*

**chemistry**

how many moles in 5g of Al? The equation says you will use 3/2 that many moles of Ag2S So, convert that back to grams of Ag2S of course, the amount of jewelry will be proportional to its surface area, not its volume.
*August 21, 2016*

**maths**

Hmmm. 24 = 2*10 + 4 24 = 2*11 + 2 You want to try that again?
*August 21, 2016*

**Calculus**

The two pieces are of length x and 100-x Since a square has four equal sides, A(x) = (x/4)^2 + ((100-x)/4)^2
*August 21, 2016*

**Math**

15mn = 15nm = (15n)m (15n)m/m = 15n
*August 21, 2016*

**maths**

but it's not!
*August 21, 2016*

**control structures**

I assume you can do the I/O The calculation is discount = (purchases > 30000) ? 0.10 : 0.02; drop that into a while loop and The I/O and you're done
*August 21, 2016*

**pre-cal**

draw a diagram review your trig functions. You will see that the height h can be found using h cot48 - h cot64 = 22
*August 21, 2016*

**Math**

area goes up as the square of the scale, so you would have 180 * 100^2 m^2 Now just convert that to hectares
*August 20, 2016*

**Math**

again? the real question is why you keep tossing in spurious apostrophes!
*August 20, 2016*

**Math**

a+w+c = 25 25a+400w+50c <= 2500 You will get a range of fruits. Or, just start with 6 watermelons cost $24 so, what can you buy with the other dollar? Not enough to make up 25 fruits. So, consider 5 watermelons for $20 Now you have $5 for the other 20 fruits. and so on
*August 20, 2016*

**Algebra**

the domain is all reals except where the denominator is zero. So, when is x^2-49 = 0 ? For the hole, note that 2x+14 = 2(x+7)
*August 20, 2016*

**algebra**

it hits the ground when the height is zero. So, just solve 256-16t^2 = 0 (16-4t)(16+4t) = 0 ...
*August 20, 2016*

**PHYSIC**

work = force * distance so, plug in your numbers.
*August 20, 2016*

**MATHS**

try using some easy numbers first. if buying 10 lbs, his scale says he is only getting 11 lbs. His selling scale says he is selling 9 lbs. See what you can do with that. Looks to me like he's losing money. Unless somehow the buying/selling is from the customer's ...
*August 20, 2016*

**calculus**

lim (e^-u^2-1)/u^2 = lim (-2u e^-u^2)/2u = -1 Now let u^2 = x^2+y^2
*August 20, 2016*

**Math**

I'll have to see where you went wrong. Too bad you didn't show your work, like me. wolframalpha says you are off: http://www.wolframalpha.com/input/?i=3+sin(+pi%2F3+(t-+((4-pi%2F2))))+-1
*August 20, 2016*

**Math**

v = A sin(B(t-C))+D max v = D+A = 2 min v = D-A = -4 So, D = -1 and A = 3 v = 3sin(B(t-C))-1 max of sinθ occurs at θ = π/2 max of sinθ occurs at θ = 3π/2 so, see what you can do with that, the way I git A and D above. Recall that the period of sin...
*August 20, 2016*

**math**

The Remainder Theorem states that the remainder is f(a). So, that means we have a^3-a^2+4a = a^3+6a+10 a^2+2a+10 = 0 This has no real solutions. I suspect a typo As written, P is never greater than Q. See http://www.wolframalpha.com/input/?i=plot+x%5E3-x%5E2%2B4x+,+x%5E3%2B6x%...
*August 20, 2016*

**math**

The look good to me. Nice work.
*August 20, 2016*

**science**

why bother asking here? google will give you immediate feedback. as will your class text!
*August 20, 2016*

**science**

uh, which data?
*August 20, 2016*

**Math**

The shares are 3x and 4x. They tell you also that 4x = 3x+6
*August 20, 2016*

**Algebra**

ok. you have x+y = 13 The value of the number is 100x+y So, reversed, it's 100y+x. So, your second equation is 100y+x = 100x+y + 297 Now just solve for x and y.
*August 20, 2016*

**math**

72 = 2^3 * 3^2 504 = 72 * 7 So, now what do you think?
*August 20, 2016*

**math**

Since 57 and 22 have no common factors, stones of 50cm will do the job. In cm, the GCF(5750,2200) = 50 So, how many stones will that take?
*August 20, 2016*

**Math**

use the info they gave you: 2x + 40 = 75 - 3x Now just find x.
*August 20, 2016*

**Maths Algebra**

d = 2v d-v = 11 Now just find d and v. Not sure what you mean by saying that after 18 years ,their ages will be twice They can't both be twice as much.
*August 20, 2016*

**Maths Mensuration**

as always for parallelograms, area = base * height and of course, cost = area * rate you can either convert the rate to cost per dam^2, or convert the area to m^2
*August 20, 2016*

**Maths discount%**

.80 * .90 = .72 so how much discount is that?
*August 20, 2016*

**math**

use the SSS property, since the diagonal is common to both triangles, and the parallel sides are congruent.
*August 20, 2016*

**CHEMISTRY**

it has no fixed crystal structure. google can provide further discussions on the topic.
*August 20, 2016*

**Finance**

just plug your numbers into the formula for the present value of an annuity. I'm sure you have one. If not, google does.
*August 19, 2016*

**Math**

well, that's (x+1)(1+2+3+...+1000), right?
*August 19, 2016*

**physics**

well, work = force * distance force = mass * g so,...
*August 19, 2016*

**Calculus**

well, what happens at each dividing point? At x = -1, the limit is 0 on the left, and -1 on the right. No good. Try the others; if the left and right limits are the same, lim f(x) exists.
*August 19, 2016*

**Math**

17.6 - 16.7 = ?
*August 19, 2016*

**math**

t = 3j t-j = 32 so, 3j-j=32 2j=32 j=16 so, t=3j=48
*August 19, 2016*

**please help with this trigonometric identity!**

For clutter reduction, let's let x = (a+b)/2 y = (a-b)/2 using the sum-to-product formulas, cosa-cosb = -2 sinx siny sina+sinb = 2 sinx cosy sina-sinb = 2 cosx siny cosa+cosb = 2 cosx cosy Now we just have -tany + tany = 0 seems legit to me.
*August 19, 2016*

**Math**

well, 5x^2+4x = x(5x+4) that should help
*August 19, 2016*

**Science**

PV=kT since P and T are constant, so is V. That is, V = (23 * 4/3 pi * 15^3)
*August 19, 2016*