Saturday

October 1, 2016
Total # Posts: 44,296

**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*

**math**

volume is length*width*depth

*August 19, 2016*

**Maths Algebra**

4*24 + 6*0.015 now just place in scientific notation pick your units

*August 19, 2016*

**Maths Algebra**

moon has mass 0.0735x10^24 kg Now you can add the two numbers, since their exponents are equal

*August 19, 2016*

**Maths Profit and Loss**

125(s-c) = 5s 125s - 125c = 5s 125c = 120s s/c = 125/120 = 25/24 So, what % gain is that?

*August 19, 2016*

**Maths Profit and Loss**

(9/4) / (10/6) = 27/20 so, what % gain is that?

*August 19, 2016*

**Maths Constructions**

construct AB,BC and AC first. Then you can add point D where needed.

*August 19, 2016*

**Maths Algebra**

while the sun is indeed about 109 times as wide as the earth, the numbers given above are wrong. If you check, 10^8/10^4 = 10^4 = 10,000, not 100 google diameter of sun, earth and you will see that this problem is bogus as written.

*August 19, 2016*

**pre calculus work**

If you really have no idea, you must not have looked at the material given you... the domain of any rational function is where the denominator is zero 5x^2+4x = x(5x+4). so, the domain of f is all reals except x = 0 or -4/5 the domain of g is all reals except x=0 I think you ...

*August 19, 2016*

**Math**

sinx = 1/2 at x = pi/6, 5pi/6 sinx = -1 at x = 3pi/2, but that's not in the domain. where did you come up with 0,pi/3,pi/2? so, pi/6, 5pi/6 are the only solutions. See http://www.wolframalpha.com/input/?i=cos2x+-+sinx+%3D+0

*August 19, 2016*

**Math**

why not write 0 <= x <= pi cos2x - sinx = 0 1 - 2sin^2 x - sinx = 0 (2sinx-1)(sinx+1) = 0 not so hard now, eh?

*August 19, 2016*

**Math**

see related questions below

*August 19, 2016*

**Maths Mensuration**

so, the outer circumference is 220 + 7*2pi now do the cost.

*August 19, 2016*

**Math**

when it's all done, you should have the total fence divided equally among the lengths and widths. So, with the two dividers, you have two long sides of length x, and 4 short sides of length y. 2x+4y = 400 x = 200-2y a = xy = (200-2y)y = 200y - 2y^2 da/dy = 200-4y da/dy=0 ...

*August 19, 2016*

**calculus**

r(t) = ⟨cos(t),sin(t),cos(6t)⟩ v = <-sin(t),cos(t),-6sin(6t)> speed is |v|, so s^2 = 1+36sin^2(6t) max speed occurs when ds/dt = 0 2s ds/dt = 216sin^4(6t) ds/dt=0 when sin(6t) = 0 I expect you can take it from there, no?

*August 19, 2016*

**Math**

50*30 - 5*5*3 = 1425m^2 cos: 5*(5*3)*30 = ?

*August 19, 2016*

**Business Calc**

f = x^2/e^(3x) = x^2 e^(-3x) f' = 2x e^(-3x) + x^2 e^(-3x)(-3) = (2x-3x^2) e^(-3x) or (2x-3x^2) / e^(3x)

*August 19, 2016*

**Math**

OOOoooommmmmmmm!

*August 19, 2016*

**math**

4 5/8 = 4 + 5/8

*August 19, 2016*

**Steve help please?!?!**

mol wt of N2O5 = 108 So, 36.7g = 0.340 moles Look at the equation. Each 2 moles of N2O5 yield 1 mole of O2. So, you will get 0.340/2 = 0.170 moles O2

*August 19, 2016*

**Rai**

depends on the radius of the circle, but it has gone 1/3 of the way around.

*August 19, 2016*

**Maths**

drop an altitude from angle A to BC and it should be clear that sin(A/2) = (a/2)/b that will give angle A, and then B = C = (180-A)/2

*August 19, 2016*

**physics**

Northeast is E45°N or N45°E. Assuming you mean E60°N, that means <10,0> + <5/2,5√3/2> + <x,y> = <0,0>

*August 19, 2016*

**phisics**

<-150,0> + <0,-50> = <-150,-50>

*August 19, 2016*

**Math**

put all those words into math: j-2 = g+2 j+2 = 2(g-2) Now just solve for j

*August 19, 2016*

**physics**

1/2^5 = 1/32 of the original amount

*August 19, 2016*