Monday

September 26, 2016
Total # Posts: 44,087

**Math**

list the pairs of factors of 60 and 75 The more factors, the more ways they can be arranged.

*August 26, 2016*

**Analogy**

eighteen:even::thirty-three:odd

*August 26, 2016*

**Chemistry**

convert to moles, then multiply by Avogadro's Number

*August 25, 2016*

**Math**

see related questions below

*August 25, 2016*

**Physics I - Modern**

it's mv/√(1 - v^2/c^2) see http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/relmom.html

*August 25, 2016*

**Math**

well, a 150lb person on the moon would weigh (150/120) * 20 = 25lb

*August 25, 2016*

**Math**

no idea. try google

*August 25, 2016*

**physics**

40 mi/hr * 1609m/mi * 1hr/3600s * 60s/min * 3min = 1073.7 m

*August 25, 2016*

**7th grade math**

clearly, two of the three possible discounts will give enough discount so that the final price with tax will be less than $25. So, probability is 2/3

*August 25, 2016*

**7th grade math**

There are 8 possible outfits with the shoes and bottoms. So, what is the smallest multiple of 8 that is at least 35? Using n tops, he gets 8n outfits.

*August 25, 2016*

**Pre-calculus**

Since the axis is horizontal, the general equation is x = a(y-k)^2 + h Since the vertex is at y=k, k = h and that means x = a(y-k)^2 + k Using the two points, we have a(-2-k)^2 + k = 6 a(4-k)^2 + k = 3 solve those, and you wind up with x = 1/4 (y-2)^2 + 2 x = 5/36 (y-14/5) + ...

*August 25, 2016*

**math**

1/4 + 5/8 + x + 3/4 = 2 1/2 Now just solve for x did you get 7/8 ?

*August 25, 2016*

**Math**

since distance = speed * time, if your speed is x, then 2*x + 2*2x = 258

*August 25, 2016*

**physics**

The ball's height is modeled by h(t) = 15t - 4.9t^2 The ball will be 8m high twice: on the way up and on the way down. These times can be found by solving 15t - 4.9t^2 = 8 See http://www.wolframalpha.com/input/?i=15t+-+4.9t%5E2+%3D+8 If you include the units in your ...

*August 25, 2016*

**MATH**

(36-30)/30 * 100

*August 25, 2016*

**Maths**

there are 48*16 food portions after 4 days, 48*4 portions have been eaten. So, there is enough for (48*16 - 48*4)/(48-12) = 16 days or, after 4 days, 1/4 of the food is eaten. That leaves enough for 12 days for the full population. But, the population is now 3/4 what it was, ...

*August 25, 2016*

**value**

m/d = 8/5 d = 15, so m=24 so, what is m-6?

*August 25, 2016*

**Maths**

start with cot(x/2) = sinx/(1+cosx) and see where you can take that.

*August 25, 2016*

**maths**

just list the factors of 72, and work with that, depending on how many piles you want: 1 72 2 36 2 2 18 2 2 2 9 ... 3 3 8 3 24 and so on

*August 25, 2016*

**alg. Connections**

total points for an 85 average: 85*3 = 255 Points so far: 81+86 = 167 So, haw many does she still need?

*August 25, 2016*

**algebra HELP MRS SUE**

B is better :-)

*August 25, 2016*

**lauren**

If $x at 11%, then the rest $(6300-x) is at 7%. So, just add up the interest: .11x + .07(6300-x) = 565

*August 25, 2016*

**value**

And surely the ratio is 4:3, not 40:3 maybe for bread 40:3 would be appropriate, as it is not so sweet as a cake.

*August 25, 2016*

**Geometry**

You may be right, but I have no diagram, so it's hard to say; but they do add up to 180°, so they are also supplementary.

*August 25, 2016*

**maths**

visit https://www.learnnext.com/nganswers/ask-question/answer/OPQR-is-a-rhombus-three-of-its-vertices-lie-on-the-circle-/Areas-Related-to-Circles/18625.htm

*August 25, 2016*

**Science**

1.5 m/hr * 1hr/3600s = 1/2400 m/s now, recall that time = distance/speed and use that what are you, a slug? Maybe you meant 1.5 km/hr. If so, jack up the speed by a factor of 1000.

*August 25, 2016*

**math**

well, just add the fractions: 1/4 + 1/3 + 1/2 + 7/12 + 3/4 + 5/6 + 1 = 3/12 + 4/12 + 6/12 + 7/12 + 9/12 + 10/12 + 12/12 = (3+4+6+7+9+10+12)/12 = 51/12

*August 24, 2016*

**Math**

assuming straight-line depreciation, then it will have lost (10/4)(.25) = .625 = 5/8 of its value So, it will be worth 3/8 of 21000 or $7875

*August 24, 2016*

**Math - Composition of Functions**

huh? really? g(x) = 1/x so, f(x) = g◦h = 1/h = 1/(x+1)

*August 24, 2016*

**math**

1xxx1 or 1xxx7 now just fill in the other 3 digits in the 6 ways possible

*August 24, 2016*

**math**

Hmmm. I see it as $54(1/6) + (1/2)($18(1/6)) = $12

*August 24, 2016*

**Math**

x y

*August 24, 2016*

**Math**

why are you guessing? I hope you actually did some kind of calculation. since cos(kx) has period 2pi/k, cos(pi/3 x) has period 6 the rate of change is y' = -pi/3 sin(pi/3 x) so, it is zero at pi/3 x = 0 or pi or 2pi; that is, x = 0,3,6 sin(pi/3 x) is at a max when pi/3 x...

*August 24, 2016*

**physics vectors**

the final vector will have x- and y-components. The direction θ is such that tanθ = y/x

*August 24, 2016*

**physics vectors**

so, get out your graph paper, plot the vectors and measure the final vector.

*August 24, 2016*

**Math**

12(3+2)

*August 24, 2016*

**math**

if the three numbers are x-1, x, x+1 then you know that x+1 = (x-1)/2 + 2 or x+1 = (x-1+2)/2 depending on how you parse the words

*August 24, 2016*

**MATH - again?**

Damon already did this one for you.

*August 24, 2016*

**calculus**

x^2+4y^2+16z^2−64 = 0 16z^2 = 64-x^2-4y^2 2z ∂z/∂x = -2x 2z ∂z/dy = -8y so, ∂z/∂x = -x/z ∂z/∂y = -4y/z ∂^2z/∂x^2 = -(x^2+z^2)/z^3 and you can do the others similarly, using the quotient rule or the product rule

*August 24, 2016*

**math**

subtracting a smaller number results in a greater difference.

*August 24, 2016*

**Economics**

Assuming that all the variable cost is labor, that would make wages for (50-30)/2 = 15 units

*August 24, 2016*

**Math**

note that this is also just (x+y)/2 + (7+17)/2

*August 24, 2016*

**Math**

(x+y)/2 = 10 (x+7 + y+17)/2 = (x+y + 24)/2 = (x+y)/2 + 24/2 = 10+12 = 22

*August 24, 2016*

**Physics**

lnx x^y + lny y^x - ----------------------------------- x^(y-1) + y^(x-1)

*August 24, 2016*

**business**

total_grade=0fori=1to4readscore[i]totalgrade+=score[i]nextiaverage=total_score/4fori=1to4displayi,": ",score[i]nextidisplay"average: ",average

*August 24, 2016*

**math**

area is circumference times height, so 14πd = 396 assuming open ends.

*August 24, 2016*

**math**

not quite sure which direction 60°north and 45°east is supposed to be.

*August 24, 2016*

**math**

no idea what x is, but each leg is 145/√2

*August 24, 2016*

**maths**

120-(60+50-20)

*August 24, 2016*

**math**

see http://www.askiitians.com/forums/Trigonometry/prove-cot-a-cot-60-a-cot-60-a-3-cot3a_106221.htm for one solution. You might try proving it without recourse to sin and cos.

*August 24, 2016*

**Kaplan**

their combined speed is 67 mi/hr so, which two numbers differ by 9 and sum to 67? x-y=9 x+y=67 ...

*August 24, 2016*

**Math**

if you use your sum-to-product formulas, you will see that the results is a real number. imaginary part is zero

*August 23, 2016*

**Math**

you have a 7-24-25 triangle, in QII cosθ = x/r = -24/25

*August 23, 2016*

**physics vectors**

A+B = 2i-7j tanθ = -7/2 in QIV A-B = 4i+5j tanθ = 5/4 in QI

*August 23, 2016*

**science**

treating the vectors as complex numbers, we have 75i + 250 + 109cis(pi/6) - 156i = 344.4 - 26.5i or, in polar form, 345.4 @ E4.4°S

*August 23, 2016*

**math help me out**

does that mean p received 80% of the profit?

*August 23, 2016*

**Maths**

assuming simple interest, you want P*.25/2*4 = 8560*0.12*5 not quite sure what 25/2% means, but if I got it wrong, just fix it.

*August 23, 2016*

**Algebra 1**

not whole numbers rational integer

*August 23, 2016*

**Math**

1 ml, 20 ml, 979 ml Pick any three distinct numbers that add up to 1000

*August 23, 2016*

**Math**

just as you cannot subtract 7 from 2 in 32 - 17 you change 32 to 20+12 Now you can borrow the 7 from 12, leaving 15 2 hrs 2 minutes is the same as 1 hr 80 minutes. Now you can subtract from a number bigger than 20.

*August 23, 2016*

**math**

assuming you can draw tallies, just make the marks, usually in groups of 4 lines with a crossing line for 5. See https://www.google.com/search?q=tally+marks&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiljfC-xdjOAhVK6WMKHdHWDDoQsAQITA&biw=1541&bih=852

*August 23, 2016*

**Algebra**

flip each side and you have 1/x + 1/y = 1/6 6/x + 6/y = 1 6x+6y = xy Not sure just where you want to go with this. Clearly, 1/2 + -1/3 = 1/6

*August 23, 2016*

**math data management**

she needs at least 4 out of the remaining 8 questions correct. So, that has probability This topic is discussed here: http://math.stackexchange.com/questions/853407/4-heads-in-8-tosses

*August 23, 2016*

**Educational Tech**

input and output

*August 23, 2016*

**Methametical literacy**

she's 60 km ahead when he starts he's going 20km/hr faster. 60/20 = 3 hrs to catch up

*August 23, 2016*

**math ASAP**

x/(x+6) = 7/9 9x = 7(x+6) 9x = 7x + 42 2x = 42 x = 21 so, x+6 = 27

*August 23, 2016*

**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*