Friday

February 24, 2017
Total # Posts: 48,773

**math**

1.1 * 0.8 = 0.88 now you can get the change.

*February 4, 2017*

**Math**

|x+1| = |x-(-1)| That is the distance from x to -1 So, on the number line, mark the two points which lie 3 units away from -1: -4 and +2 Shade the area between those two points, where the distance from -1 is less than 3.

*February 4, 2017*

**Math**

Of course there is, though its form will depend on how the trapezoid is described. For simplicity, let's say that the bottom base goes from (0,0) to (a,0) and that the top base goes from (b,h) to (c,h). (Usually, this will mean that 0<=b<=c<=a) The area of the ...

*February 4, 2017*

**Calculus**

Just use the normal product and chain rules, with the chain rule: f=uv, f' = u'v+uv' f=u/v, f' = (u'v-uv')/v^2 Just take it a step at a time; you know how to get the derivatives of the various function involved. If you get stuck, come back with your ...

*February 3, 2017*

**Calculus**

just use the chain rule (a) h' = f'g + fg' = (12)(-3)+(-7)(-9) = 27 (b) h' = (f'g-fg')/g^2 = ((12)(-3)-(-7)(-9))/(-3)^2 = -11 (c) h' = (g'(1+f^2))-g(2ff'))/(1+f^2)^2 = ((-9)(1+(-7)^2))-(-3)(2(-7)(12))/(1+(-7)^2)^2 = -281376/625

*February 3, 2017*

**Algebra2**

thank you

*February 3, 2017*

**Algebra2**

Solve the equation 3^5sqrt(x+2)^3+3=27 My answer is 30

*February 3, 2017*

**Math**

well, she bought m pens, and each cost 6.70 So, the total cost for the pens is 6.70m same for the pencils, but there are m-4 of them.

*February 3, 2017*

**math**

correct I hope x is small, to be realistic...

*February 3, 2017*

**math**

2/13 + 1/3 = 6/39 + 13/39 = 19/39 so, 19/39 - 1/3 = 2/13

*February 3, 2017*

**Math help PLEASE!!!!**

sorry - can't see files on your computer.

*February 3, 2017*

**Geometry**

Divide it up into rectangles and triangles, which are easy to figure.

*February 3, 2017*

**algebra**

If the number is abc, then you are told a+b+c = 20 b = (a+c)/2 100c+10b+a = 100a+10b+c + woo Now just solve for a,b,c

*February 3, 2017*

**math**

review the 2nd Fundamental Theorem of Calculus. If ?ln(2t+1) dt = f(t), then G(x) = f(x) - f(1) So, naturally, G'(x) = ln(2x+1) the 2nd integral is just

*February 3, 2017*

**calculus**

the square has base 2y=2?x and height 2y=2?x and thickness dx So, v = ?[0,9] (2?x)(2?x) dx = ?[0,9] 4x dx ...

*February 3, 2017*

**physic**

well, the density of the mass is m/v So, how much of that is buoyed up by the liquid? Then the tension is the difference, times g.

*February 3, 2017*

**chem**

1 mole of a suitable substance.

*February 3, 2017*

**math**

a+16d = 3a-6 a = 8d+3 So, pick d and you have a: d=1, a=11 11,12,13,...,27 27 = 3*11-6 d=0, a=3 3,3,3,...,3 3 = 3*3-6 As you can see, any value of d will work.

*February 3, 2017*

**Maths**

see related questions below

*February 3, 2017*

**math**

sinB/b = sinA/a I suspect a typo

*February 3, 2017*

**maths**

just check all the pairs where one is a multiple of 7 and the other is not.

*February 3, 2017*

**maths**

sorry. 210 = 5*7 * 2*3

*February 3, 2017*

**maths**

210 = 5*7*3 ...

*February 3, 2017*

**Math**

h/w = 4/3 (h+4)/(w+4) = 9/7 h=32, w=24 (h-m)/(w-m) = 5/3 (32-m)/(24-m) = 5/3 m=12 They were married 12 years ago, when the ratio of their ages was 20/12 = 5/3 She was a child bride!

*February 3, 2017*

**Math**

That would be 55C26 (-3x)^29 (4y)^26 I'll let you do the arithmetic. Expect some large numbers!

*February 3, 2017*

**Math**

p(k) = 2k+5 k(p) = 3p+b 2k(x)+5 = 3p(x)+b b = 2k(x)-3p(x)+5 Unless you have some further information on the functions p and k, that's as far as we can go.

*February 3, 2017*

**4th grade math**

Harriet ate 1/4, leaving 3/4 uneaten. Nisha ate 1/2 of the 3/4, or 3/8, leaving 3/8 uneaten. 6 pieces was 3/8, so the whole bar was 6 divided by 3/8, or 6 * 8/3 = 48/3 = 16 pieces. Check Harriet ate 1/4, or 4 pieces, leaving 12. Nisha ate 1/2 of those, leaving 6. Works for me...

*February 2, 2017*

**Math**

a = d+15 time = distance/speed, so 440/d = 560/a Now substitute for a, and you get 440/d = 560/(d+15) Now you can solve for d, and then get a.

*February 2, 2017*

**Math**

If the radius is 23 yd, then the area is 3.14 * 23^2 = 1661.06 yd^2 If the diameter is 23 yd, divide that by 4.

*February 2, 2017*

**maths**

f(x+h)-f(x) = 3/(2(x+h)-1) - 3/(2x-1) = [3(2x-1) - 3(2x+2h-1)]/[(2x-1)(2(x+h)-1)] = (6x-3-6x-6h+3)/[(2x-1)(2(x+h)-1)] = -6h/[(2x-1)(2(x+h)-1)] now divide that by h to get -6/[(2x-1)(2(x+h)-1)]

*February 2, 2017*

**Calculus**

see related questions below. Recall that if a is a root, (x-a) is a factor.

*February 2, 2017*

**Algebra**

depends on the half-life. If it is t years, then it will take x years, where (1/2)^(x/t) = 0.7 x/t = log0.7/log0.5 x = 0.5145t years

*February 2, 2017*

**Math**

and besides, a 48% solution of what?

*February 2, 2017*

**math**

?((-4+3)^2+(-1-8)^2) = ?((-1)^2+(-9)^2) = ?(1+81) = ?82

*February 2, 2017*

**Math**

GCD(12,20) = 4 So, 4 teams of 3 girls and 5 boys each

*February 2, 2017*

**Math**

what does a low correlation coefficient mean? What kind of value indicates a "close" approximation?

*February 2, 2017*

**Business**

is money your employer pays for your medical insurance part of your gross income? My answer is no

*February 2, 2017*

**Business**

Thank you-- just checking

*February 2, 2017*

**Business**

Are standard deductions tax breaks that you can claim without having to itemize? My answer is yes

*February 2, 2017*

**Business**

Thank you

*February 2, 2017*

**Business**

Which of the following is not true about you adjusted gross income? 1- income minus deductions 2-income plus deductions 3- determines if your eligible for additional tax breaks 4- gross income minus deductions my answer is 2

*February 2, 2017*

**Math**

4 + 9^2/3 * 2 - 2 = 4+27*2-2 = 4+54-2 = 56 (4+9)^2 / (3*2-2) = 169/4 You need to use math notation to make it clear how the numbers are grouped. Once you do that, evaluating it is easy.

*February 2, 2017*

**Math**

oops, (7+5)*6+3

*February 2, 2017*

**Math**

(7+5)*6-3

*February 2, 2017*

**Maths**

0.8m/0.5s = 1.6 m/s

*February 2, 2017*

**Math**

so the formats are different. So what? Rearrange them so they are the same! 5x - 4y = -3 3x + y = 5 Now you can manipulate them. Or, since you know that y = -3x+5, use that in the other equation: 5x - 4(-3x+5) = -3 Solve for x, and then get y.

*February 2, 2017*

**Math**

(5/8) / (1 1/4) = 5/8 / 5/4 = 5/8 * 4/5 = 1/2 hour

*February 2, 2017*

**Algebra Square Roots**

you want 39x to have two factors of 3 or 13 That means x=6, giving us ?(39*6) = ?(3*13*3*2) = 3?26 Not sure that's really any simpler.

*February 2, 2017*

**Math**

so why don't you show us what you did? One way is to notice that 14 = 7*2, so if we double the 2nd equation, we get 8x + 14y = 24 12x + 14y = 20 Now if we subtract the equations, the y's cancel out, and we get -4x = 4 x = -1 Now use that in either equation to get y. 8...

*February 2, 2017*

**Math**

1 hour is 60 minutes, so 1/5 hour = 12 minutes 1/4 hour = 15 minutes So, 3 2/5 hr = 180+24 = 204 min 4 3/4 hr = 240+45 = 285 min

*February 2, 2017*

**Math**

a varied directly as b means that there is some constant k such that a = kb That means that a/b = k and is constant. Thus, you want b such that 4/20 = 50/b 4b = 1000 b = 250 Or, since 50 is 12.5 * 4, b = 12.5*20 = 250

*February 2, 2017*

**Math**

That does sometimes happen. If they had $440 in total, then you'd have 14t = 700 t = 50 That seems most likely.

*February 2, 2017*

**Math**

rather than guessing, do the math f = t-20 j = 3f = 3(t-20) = 3t-60 p = 3j = 3(3t-60) = 9t-180 f+t+j+p = 340 Now you can solve the equations, knowing that the sum will be 340. f+t+j+p = t-20 + t + 3t-60 + 9t-180 = 340 14t-260 = 340 14t = 600 t = 300/7 Hmmm. I get a fraction, ...

*February 2, 2017*

**Math**

Just do what you always do when solving for a variable. Move things around till it is all alone x/y = (x+a-b)/z As usual, just cross-multiply to clear the fractions xz = y(x+a-b) xz = xy + y(a-b) xz-xy = y(a-b) x(z-y) = y(a-b) x = y(a-b)/(z-y)

*February 2, 2017*

**maths**

Suppose we let a = math only b = English only c = science only x = math and science only y = math and English only z = English and science only If you draw the Venn diagram, you see that a+b+c = 36 a+x+y+4 = 22 b+y+z+4=21 c+x+z+4=25 Solve those equations and you get x = b-7 y...

*February 2, 2017*

**calculus**

if x<3, x-3 < 0 5/0 = ? but if the denominator is negative, it is -? Let u = x-3 Then you have the limit (y -> 0-) 5/u The limit is unbounded, and it is negative.

*February 2, 2017*

**calculus**

see http://www.jiskha.com/display.cgi?id=1485970773

*February 2, 2017*

**Math**

you have a geometric progression, with a = 1000 r = 1.5 S5 = 1000(1.5^5-1)/(1.5-1) = 13187.5 The answer key is wrong.

*February 2, 2017*

**Math**

there are lots of fractions in between 1/2 and 1: 1/2 < 4/7 < 3/5 < 5/8 < 2/3 < 3/4 < 1

*February 2, 2017*

**Math**

(7/2)/(3/7) = 7/2 * 3/7 = 3/2 or, 1.5 pieces. You let the fractions scare you. I expect you could solve the problem using easier numbers: How many pieces of 2 feet each can I make out of 10 feet of rope?

*February 2, 2017*

**math**

yes, 38<43 so, what is the answer to the question.

*February 2, 2017*

**math**

n/m

*February 2, 2017*

**Grammar**

there is an implied verb at the end: No one likes tropical fish more than [does]. So it is clearly "she" and not "her". This brings up a common mistake. Many people say My mom likes cookies more than me. meaning that mom is very fond of cookies. But what ...

*February 1, 2017*

**6 grade math**

If a hip-hop jump moves a distance of x feet, then his jumps add up (to the right) to 12+x+x-3-(3*3)+16 = 16+2x I have no idea how far it is from A to B, but if you say he ended at 24, then 2x = 8, and a hip-hop jump is 4 ft.

*February 1, 2017*

**math**

hard to say. They scored 69 pts in all three games. They ask about "the winning game". There were two of them. Assuming they meant "the winning games" then they scored 27+24=51 pts. The score in the losing game is irrelevant.

*February 1, 2017*

**Math**

If you say so

*February 1, 2017*

**Help! Calculus**

?(x^2+1) dy/dx - x/(2y) = 0 ?(x^2+1) dy/dx = x/(2y) 2y dy = x/?(x^2+1) dx y^2 = ?(x^2+1) + c y(0)=1, so 1 = 1+c c = 0 y^2 = ?(x^2+1) y = ?(x^2+1)

*February 1, 2017*

**Math**

1 gal = 8 pt so, use 1/8 of 2 cups of concentrate since 2c = 16 floz, you would use 2 fl oz of concentrate

*February 1, 2017*

**math**

each wire has length x, where x^2 = 18^2 + 47^2

*February 1, 2017*

**value**

density is mass/volume

*February 1, 2017*

**algebra 1**

xy = k so, 2*3 = k k = 6 y = 6/x now fill in the table.

*February 1, 2017*

**Algebra II**

Oops. You missed my typo. The slope is -12. y-4 = -12(x-1) y = -12x + 16

*February 1, 2017*

**Algebra II (plz)**

No problem. I was just working on it when you reposted. It had been almost two hours, and your posting was working its way down the page to obscurity, so it was understandable. The nuisances are people who repost every five minutes and expect someone to be monitoring their ...

*February 1, 2017*

**Algebra II (plz)**

see your earlier post

*February 1, 2017*

**Maths**

y-x = 2.38 y = 3x x+y = 6 You only need two of the equations to solve for x and y. As it happens, there is no solution to all three conditions: Using y-x = 2.38 y = 3x 3x-x = 2.38 2x = 2.38 x = 1.19 y = 3x = 5.37 Fails to satisfy x+y=6 or, using y-x = 2.38 x+y = 6 2x = 8.38 x...

*February 1, 2017*

**College Algebra**

distance = time * speed Let b = boat's speed c = current's speed 5(b-c) = 100 2(b+c) = 100 b-c = 20 b+c = 50 I guess you can take it from there, yes?

*February 1, 2017*

**algebra 1**

since you have no values for y, you cannot determine k.

*February 1, 2017*

**College Algebra**

If that is 1/(x+9), then just plug and chug: f(x+h)-f(x) = 1/(x+h+9) - 1/(x+9) = [(x+9)-(x+h+9)]/[(x+h+9)(x+9)] = (-h)/[(x+h+9)(x+9)] That is the difference. The difference quitient is just that divided by h, so it is -1/[(x+h+9)(x+9)]

*February 1, 2017*

**calculus**

lim(4-g(x))/x = So, 4-g(x) must also approach 0, or the limit would be ±?. Thus, lim g(x) = 4 If you meant 4 - g(x)/x then of course, lim g(x) would be 0, by the same logic.

*February 1, 2017*

**calculus**

?(x^2+x) - ?(x^2-x) (?(x^2+x) - ?(x^2-x))(?(x^2+x) + ?(x^2-x)) ------------------------------------ ?(x^2+x) + ?(x^2-x) (x^2+x)-(x^2-x) ------------------------------- ?(x^2+x) + ?(x^2-x) = 2x/(?(x^2+x) + ?(x^2-x)) divide top and bottom by x (?x^2) = 2/(?(1 + 1/x) + ?(1 - 1/x...

*February 1, 2017*

**math**

y = 45+30x

*February 1, 2017*

**Math (please check my answer!!)**

looks correct. You neglected to mention that X is the intersection of the diagonals.

*February 1, 2017*

**Algebra (check answers plz)**

Find the slope of the line that contains the two points (3,2) and (1,-4). slope is ?y/?x = (-4-2)/(1-3) = -6/-2 = 3 Find the slope of the line that contains the points (-2, 4) and (-4, 6) slope is (6-4)/(-4-(-2)) = 2/-2 = -1 >b>Find the equation of the line that passes ...

*February 1, 2017*

**Geometry**

the only biconditional in the list is C. As it happens, it is also the correct choice. >whew<

*February 1, 2017*

**Maths: Surds**

if the length is x and the height is y, we need y/x = (x/2)/y x^2 = 2y^2 x = ?2 y since xy = 100?2 y=10 x=10?2

*February 1, 2017*

**Math**

Just figure the height above the people, and then add 2 meters. Draw a diagram, and it will be clear that if h is the height above the boaters, h cot12° - h cot16° = 50

*February 1, 2017*

**trigonometry**

r=12 C = 2?r 3 rev/min * 24? ft/rev * 1min/60s = 72?/60 = 6?/5 ft/s

*February 1, 2017*

**Math**

just replace x with whatever quantity you have f(p) = 2p-9 f(x+h) = 2(x+h)-9

*February 1, 2017*

**Carpentry**

assuming the plywood is 3/4" thick, then we have to worry about which direction the shelves are laid out. If the 13" width is parallel to the 48" width of the sheet, then discarding the wastage, we get 48/13 x 96/18 = 3.6 x 5.3 or 15 shelves If laid out the ...

*January 31, 2017*

**basic calculus**

since the topic is calculus, I guess they want to show that y' = -(3x^2+2xy)/(x^2+4y)

*January 31, 2017*

**Geometry**

I will assume the octagon is regular, so each side is 3.5/8 = 7/16. Now just divide the octagon into eight isosceles triangles, each with base 7/16 and vertex angle 45°. The area of each triangle is easy to do, and just multiply it by 8.

*January 31, 2017*

**basic calculus**

Just google area of torus. You will need to know the inner and outer radii of the ring, as well as the radius of the metal wire.

*January 31, 2017*

**Precalculus**

Not sure how you can call x and y points, and then use them as values in an expression. Most precal courses don't cover vectors, and even so, the expression is not a valid vector computation. I guess you could use complex numbers for the points, and then they would be x...

*January 31, 2017*

**Precalculus**

Hmmm. You're right. It's 2?/3

*January 31, 2017*

**Math**

no idea. how much did he have left?

*January 31, 2017*

**Math**

(236-150)/9 = 86/9 = 9.6 so, about 10 more days

*January 31, 2017*

**algebra**

(14)(-3y^-4)/(2*5y^-2) = -42y^-4 * y^2/10 = -21/5 y^-2 If I got the wrong interpretation, maybe you can use some more standard notation to try it again. Try using * for multiplication ^n for raising to the nth power and don't forget parentheses if there is more than one ...

*January 31, 2017*

**math**

-2y

*January 31, 2017*

**Math**

first question: do you know what the order of a function is? The term "order" has several meanings. Do you maybe mean degree of a polynomial? If so, then it's the highest power of the variable.

*January 31, 2017*

**math**

well, each bag weighs 1/2 lb. How many halves in 12?

*January 31, 2017*