Wednesday

February 10, 2016
Total # Posts: 37,540

**Math**

well, there are 57/y bananas That means there must be only 57/y apples, so the result will be 57/y oranges, each having mass x+y so, the mass of oranges will be 57(x+y)/y = 57(1+x/y) grams
*February 3, 2016*

**Math**

as always, swap variables and solve for y: 3x+5y=18 5y = 18-3x y = (18-3x)/5 Did the other one in your previous post (see related questions below)
*February 3, 2016*

**Math**

I think you are missing something. Each added triangle has a smaller area and a smaller perimeter. I think I am missing something, too. If all the triangles are inscribed into the same area, the total area is unchanged, right? By "the perimeter" do you mean the sum ...
*February 3, 2016*

**physics**

log1519
*February 3, 2016*

**math**

y = 144+(115.2-144)/(14) x = 144-2.057x Now just plug in values for x.
*February 3, 2016*

**Algebra**

(6x^-2)^2 = 36 x^-4 (1/2 x)^4 = 1/16 x^4 multiply and you get 36/36 = 9/4 = 2.25 If you want us to analyze your work, you need to show it!
*February 3, 2016*

**algebra**

if there are all positive exponents, then it is a polynomial. Terms are separated by +/- signs, so just count the terms to determine the type. Add the exponents in each term; the highest sum is the degree of the polynomial.
*February 3, 2016*

**science/maths**

divide those time values by 60, since they are in minutes, not hours.
*February 3, 2016*

**Algebra**

If the slow plane's speed is x mi/hr, then since distance=speed*time, 4x + 4(x+65) = 2660
*February 3, 2016*

**Algebra**

f◦g = f(g) = 3/(g-3) = 3/((2/x)-3) = 3/((2-3x)/x) = (3x)/(2-3x) It looks like the domain of f◦g is all reals except x=2/3, but we also have to exclude x=0, since g is not defined there.
*February 3, 2016*

**math**

it is just the product of the two primes, since there are no common factors.
*February 3, 2016*

**maths**

review the definition of cot(x). Draw a diagram and you can see that h*cot45 - h*cot60 = 100
*February 3, 2016*

**math**

Take a look at this site to see a very similar problem: https://www.quora.com/If-2f-x-3f-left-frac-1-x-right-+-x-2-then-f-2
*February 3, 2016*

**Algebra**

y(t) = y(x(t)) = ln(2*4e^(t/2.5)) = ln(8) + ln(e^(t/2.5)) = ln8 + t/2.5 ≈ 0.4t + 2.08
*February 3, 2016*

**Math**

what you have is an ellipse with semi-axes of 30 and 20 ft, with the long axis horizontal. So, if the center is placed at (0,0) the equation is x^2/30^2 + y^2/20^2 = 1 So, the upper arch is y = 4/9 √(900-x^2) Now just plug in your various values for x to find the height y.
*February 3, 2016*

**Math**

4z-6u
*February 3, 2016*

**math**

1 degree of latitude is approximately 111 km. So, 500km south takes you to 50-500/111 = 4.5°N Naturally, the longitude has not changed.
*February 3, 2016*

**math**

3(m-5)=6m-60 3m-15 = 6m-60 3m=45 m=15 check: 3*(15-5) = 30 = 6*15-60
*February 3, 2016*

**Michael**

probably infinitely many, but the smallest is 1729 = 1^3 + 12^3 = 9^3 + 10^3 as G.H. Hardy learned from Ramanujan.
*February 3, 2016*

**maths**

Hint - think of a 5-12-13 right triangle.
*February 3, 2016*

**singaporean math ratio**

3/7 spent leaves 4/7 1/4 of 4/7 is 1/7, so 3/7 left 3/7 x = 120
*February 3, 2016*

**math**

clearly, that would be 20/50
*February 3, 2016*

**math**

Nope. 30 are boys.
*February 3, 2016*

**geometry**

This is discussed here: https://en.wikipedia.org/wiki/Semiperimeter
*February 3, 2016*

**Numerical Analysis**

well, I don't know what a has to do with x, but pull out your calculator, or use one of the many online calculators, and you can easily learn that tan(1.7) = -7.7 That would have been a lot faster than posting a question like that and having to wait for an answer.
*February 3, 2016*

**Math**

(1/2)(h-2)(h) = 60 Now just solve for h
*February 3, 2016*

**Math**

200+49*2
*February 3, 2016*

**Science**

well, the water was 480 g, so that's 480mL.
*February 3, 2016*

**ACT Prep**

points so far: 72+94+85+83+97 = 431 points needed: 6*88 = 528 Points needed on 6th exam: 528-431 = 97
*February 3, 2016*

**math**

width=w length=2w-8 2(w + 2w-8) = 194
*February 2, 2016*

**Math (precalculus)**

Let the rectangle have width x and height y=33-3x^2 clearly the area is a = xy = x(33-x^2)
*February 2, 2016*

**math**

so, list them all: 1,1 1,2 ... 5,4 5,5 Now -- how many of them have matching spins?
*February 2, 2016*

**Geometry**

that would be (-3,1) + (11+3,9-1)/4 = (-3,1)+(7/2,2) = (1/2,3)
*February 2, 2016*

**Math**

looks good.
*February 2, 2016*

**Math Need Immediate Help????**

how can f(x) include y? h = -4.9(t+3)^2+45.8 h^-1 = √((45.8-t)/4.9)-3
*February 2, 2016*

**differential equations**

what's the trouble? Expand the right side and you have dS/dt = k/MN (-S^3 + (M+N)S^2 - MNS) That's just a polynomial, which you can easily integrate to find S(t)
*February 2, 2016*

**Calculus(PLZ HELP)**

just check out the volume of a spherical cap: http://mathworld.wolfram.com/SphericalCap.html
*February 2, 2016*

**precal**

arctan(3/4) ≈ 37° P is in QIV, so θ = -37° or θ = 360-37 = 323°
*February 2, 2016*

**Math/Algebra**

since time = distance/speed, d/36 + d/48 = 7/2 4d/144 + 3d/144 = 504/144 7d = 504 d = 72 mi
*February 2, 2016*

**math (factorising by grouping )**

skill comes from experience. Just look for common factors. 2ax-6bx+ay-3by You have a 2and a 6, and a 1 and a 3. So, 2x(a-3b)+y(a-3b) (2x+y)(a-3b) Now you try the others.
*February 2, 2016*

**Calc II**

best to use discs of thickness dx. So, v = ∫πr^2 dx where r = 6-y. So, v = ∫[-π/2,5π/2] π(6-(3sinx+3))^2 dx = 81π^2/2
*February 2, 2016*

**Pre-Calc**

Unless they say something, I'd assume QI. In that case, sinθ=5/13 and cosθ=12/13 sinx=3/5 and cosx=4/5 cos (θ+x) = (12/13)(4/5)-(5/13)(3/5) = 33/65 Usually they specify a quadrant if they want to make you determine the sign of the quantities involved.
*February 2, 2016*

**Math**

no formula -- just write down the facts: If pants cost p and shirts cost s, then 3s+2p = 85.50 3s+4p = 123.00 You can now solve for s and p.
*February 2, 2016*

**MATHS**

NOTE THAT Y=11-3X NOW USE THAT IN THE 2ND EQUATION!! 2X-(11-3X) = 4 NOW YOU CAN FIND X, AND THEN Y!! CAN YOU HEAR ME? AM I SHOUTING LOUD ENOUGH???!!
*February 2, 2016*

**Pre-Calc Answer Check**

right on both.
*February 2, 2016*

**Language**

Looks like A or B to me. Two enemies are mentioned, but the eight mentions of quickness and the final friendly offering make me prefer A.
*February 2, 2016*

**Math**

try the addition formulas: 3 cos (ωt + 2) = 3(cosωt cos2 - sinωt sin2) 4 sin(ωt+1) = 4(sinωtcos1 + cosωtsin1) adding them up you get 3cosωtcos2+4cosωtsin1 + 4sinωtcos1 - 3sinωtcos2 Now, according to wolframalpha.com, that gives...
*February 2, 2016*

**Math help please**

9:7
*February 2, 2016*

**algebra**

x+y=5 2x+y=2 Now just solve for x and y
*February 2, 2016*

**eglish**

at least the sentence is correctly written.
*February 2, 2016*

**Math**

#1 ok #2 not quite #3 nope. See all those 9's?
*February 2, 2016*

**SO HARD! MATH**

First, decide whether you are going to stack them on their faces, or on their edges.
*February 2, 2016*

**algebra**

2(a-3) = b+3 a+5 = 2(b-5) A has $11, B has $13
*February 2, 2016*

**Math Help**

No diagram, but probably A, if the two form a straight line.
*February 2, 2016*

**chemistry**

write the balanced equation, then compare ratio of the number of moles of each.
*February 2, 2016*

**algebra**

If the woman is w, and the son is s, then we know w-7 = 4(s-7) w+7 = 2(s+7) woman is 35, son is 14
*February 2, 2016*

**math**

doesn't look like one to me. It's an equation.
*February 2, 2016*

**mathematics extension**

not sure. What was the question? distance from start? bearing from start to finish? Name of pilot?
*February 2, 2016*

**Math**

well, the slope is undefined; the line is vertical. So, the line is x=5 The line y=11 has zero slope. So, the line through (2,-5) is y = -5
*February 2, 2016*

**Maths**

y = x(x+4) The roots are at 0 and -4, so the vertex is at -2. see http://www.wolframalpha.com/input/?i=x^2+%2B+4x
*February 2, 2016*

**math-Polya**

not sure about Polya, but the maximum-area quadrilateral is a square. as for the circle, since c = 2πr and A = πr^2, A = c^2/(4π)
*February 2, 2016*

**Math**

The total points are not 13, but 35+10 = 45. So, using x,y,z for the scoring plays in the same order as described above, 6x+y+3z = 45 x = y x = 6z You certainly don't need elimination for this, since the substitutions are so easy.
*February 2, 2016*

**algebra**

since v = Bh, you have 264 = 48h ...
*February 1, 2016*

**Calculus**

First off, the equation should be (f(x+h)-f(x-h))/(2h) if f(x) = a(x-b)^2+c, then f(x+h) = a(x-b+h)^2+c f(x-h) = a(x-b-h)^2+c f(x+h)-f(x-h) = a((x-b +h)^2 - (a-b -h)^2 = 4ah(x-b) divide that by 2h and you have 2a(x-b) Now, f'(x) = 2a(x-b) ta-daa
*February 1, 2016*

**Precal**

enter your coefficients here: http://www.gregthatcher.com/Mathematics/GaussJordan.aspx
*February 1, 2016*

**math**

well, if you got 100% on all your tests, that would account for 70% of your grade. So, you'd then need at least 33.3% on the homework. But, if you scored 100% on all the homework, that would account for 30% of your grade, so you'd need 71.43% on the tests. So, the ...
*February 1, 2016*

**More math**

all correct. good work.
*February 1, 2016*

**Math**

if there are c chickens, then there are 40-c cows. So, adding up the legs, 2c + 4(40-c) = 100
*February 1, 2016*

**Do I have enough time**

Don't forget that you will have to spend a half hour correcting your spelling and grammar, too!
*February 1, 2016*

**Math**

If I read your language correctly, there is a 5m border around the field. So, if the dimensions of the whole area is 130x85, then the field is 120x75.
*February 1, 2016*

**Math**

as usual, k∘d = k(d) = √(d^2+100) = √((35t)^2+100) assuming t is in hours.
*February 1, 2016*

**math**

NO! Read we wrote!!! The sides are 9 over √2
*February 1, 2016*

**math**

If the diagonal is d=x√2, then x = d/√2 you did d*√2 instead.
*February 1, 2016*

**Biology**

Wine is made by mixing yeast with grapes and allowing the yeast cells to undergo fermentation. Sparkling wine is a type of wine that contains high levels of dissolved carbon dioxide. What is the source of the carbon atoms in the carbon dioxide found in sparkling wine? ethanol ...
*February 1, 2016*

**Biology**

I'm sorry I meant c
*February 1, 2016*

**Biology**

What would most likely happen to cells placed in fresh water? a- water would flow out because they are hypotonic to the external environment b- water would flow into them because they are hypotonic to the external environment c- water would flow out of them because they are ...
*February 1, 2016*

**math**

assuming you want integer values, just find the factors of 389 Hmm. 389 is a prime number. So, just pick any value (x) for the width and the length is 389/x. I suspect a typo.
*February 1, 2016*

**chemistry**

HCl + NaHCO3 = NaCl + H2O + CO2
*February 1, 2016*

**Math**

That is correct.
*February 1, 2016*

**Geometry**

4(1)-4(-1)+2 = 4+4+2 = 10 ??
*February 1, 2016*

**Geometry**

I don't see any choices which work. I suspect a typo.
*February 1, 2016*

**Geometry**

That does not work: 2(1)-2(-1)+2 = 6 Better try again.
*February 1, 2016*

**Math**

seems so.
*February 1, 2016*

**Science**

since F = 9.5 N/m, you want W = ∫[0,0.06] 9.5 x dx = 0.0171Nm = 0.0171J see http://www.intmath.com/applications-integration/7-work-variable-force.php
*February 1, 2016*

**Math**

it is only one of them.
*February 1, 2016*

**Math**

see previous post.
*February 1, 2016*

**Math**

yes.
*February 1, 2016*

**Math**

yes
*February 1, 2016*

**algebra**

just substitute 8 for each of the t's and add up teh numbers.
*February 1, 2016*

**Geometry**

The sides are 2x,3x,4x Add them up and you have 9x=45 ...
*February 1, 2016*

**Geometry**

The angles are 3x,4x,5x Sum them up and you have 12x=180 Now find x, and thus the angles.
*February 1, 2016*

**Math**

Recall that for a cubic polynomial ax^3+bx^2+cx+d, the sum of the roots is -b/a. The sum of the roots is -3-1+5 = 1 So, only A is the answer.
*February 1, 2016*

**Science**

looks good to me.
*February 1, 2016*

**Math**

Find functions of f•g, g•f, and their domains. f (x)=sqrtx-1, g (x)=x^2 Thank you very much
*February 1, 2016*

**maths**

9/2 (2a+8d) = 216 (a+2d)/a = (1+6d)/(a+2d) One choice is 24, 24, 24, ... Probably not what you want. So, let's try 8, 12, 16, ...
*February 1, 2016*

**Pre-Algibra**

pi r^2 h = v 3.14 * r^2 * 14 = 718.4 Now just find r.
*February 1, 2016*

**Math**

just scramble DEF in the same order as ABC. clearly the 1st and last choices are wrong...
*February 1, 2016*

**math**

If Z is the vertex, then the other two angles are (180-25)/2 If Z is one of the base angles, then other is also 25, and the vertex angle is 130
*February 1, 2016*

**math**

funny thing -- it looks like every other sine wave... http://www.wolframalpha.com/input/?i=sin%281*pi*1000t%29+%2B2 No idea what v(t) has to do with it, though.
*February 1, 2016*

**Math**

you could be right.
*February 1, 2016*