Sunday

December 4, 2016
Total # Posts: 46,790

**maths need help**

log_9(a+3)-log_9(b) = c + (1/2) log_3(a-3)+log_3(b) =c - 1 (a+3)/b = 9^(c+1/2) (a-3)b = 3^(c-1) (a+3)/b = 3*9^c (a-3)b = 3^c/3 a+3 = 3b*3^(2c) 3(a-3)b = 3^c 3(a+3)(a-3)b = 3b*3^(3c) a^2-9 = 27^c a^2 = 9+27^c I expect you can get the rest.

*November 22, 2016*

**Maths**

well, since y=15-2x^2, just solve 3x+9(15-2x^2) = 1 18x^2 - 3x - 134 = 0 now just use the quadratic formula

*November 22, 2016*

**Math**

you sure you don't mean a^4 - 13a^2 + 36 ? let u = a^2 and try factoring u^2-13u+36 which two factors of 36 add to 13?

*November 22, 2016*

**maths**

The diagonals bisect each other, and also meet at an angle of 125°. So, the long side of the parallelogram can be found using the law of cosines. Let the parallelogram be ABCD and the center be E. AB^2 = 3^2+4^2 - 2*3*4*cos125° AB = 6.2262 Now, the altitude of triangle...

*November 22, 2016*

**maths**

(6/2)^2 * h = 2/3 (15/2)^3 h = 125/4

*November 22, 2016*

**Maths**

Hmmm. what two factors of 36 add to 13? Try factoring u^2-13u+36 and let u=x^2

*November 22, 2016*

**Calculus**

let u = cos(3x) and see what happens

*November 22, 2016*

**Calculus**

Good luck with this - an elliptic integral.

*November 22, 2016*

**Math**

well, there are 60 minutes in an hour, so just divide by 60. Hint -- it is not 56 mi/min

*November 22, 2016*

**Math**

Take a look here, and all will become clear. https://in.answers.yahoo.com/question/index?qid=20130823004513AAdmLmh

*November 21, 2016*

**Math**

If the roots are p and rp, then you have b/a = -(p+rp) c/a = p*rp see what you can do with that

*November 21, 2016*

**Physics- Equilibrant Force**

The resultant force is 71 NE So, the equilibrant force is 71 SW

*November 21, 2016*

**Physics- Accleration of a Falling Penny**

if the force increases (more upward) the the net downward force must decrease. So, (a) since F=ma

*November 21, 2016*

**algebra**

how about fixing the formatting?

*November 21, 2016*

**dav chd**

let x = w-1 x^4-4x^3+2x^2+4x+4 = (w+1)^4 - 4(w+1)^3 + 2(w+1)^2 + 4(w+1) + 4 ...

*November 21, 2016*

**Econ math/logarithms**

8 = 2^3 log8 = 3 log2 = 3*0.39 = 1.17

*November 21, 2016*

**Gauss-Jordan elimination**

fix your typo and visit http://www.gregthatcher.com/Mathematics/GaussJordan.aspx for all the details

*November 21, 2016*

**Calculus**

You know that lim sinu/u = 1 so, lim tanu/u = 1 (because lim cosu = 1) So, lim tan(7x)/x = lim (tan(7x)*7)/(7x) = 7 lim tanu/u where u7x = 7 or, using L'Hospital, lim tan(7x)/x = lim (7 sec^2(7x))/1 = 7

*November 21, 2016*

**Trig**

You know that the standard parabola x^2 = 4py has focus at (0,p) and directrix at y = -p. Your parabola has been shifted so its vertex is at (-2,6). 4p=8. So, the focus is 2 above the vertex and the directrix is 2 below the vertex.

*November 21, 2016*

**math**

Let the printed area xy=50 The total area is a = (x+2)(y+4) = (x+2)(50/x + 4) = 4x + 58 + 100/x so, find where da/dx = 0 (and x>0)

*November 21, 2016*

**math**

it is the slope of the line joining (1,f(1)) and (2,f(2)): (1,20/4) and (2,20/16) (20/16 - 20/4)/(2-1) = ?

*November 21, 2016*

**Math**

s shares at price p gives sp = 308 (s+6)(p-3) = 308 sp+6p-3s-18 = 308 308+6p-3s = 18 2p-s = 6 2p - 308/p = 6 2p^2 - 6p - 308 = 0 p^2 - 3p - 154 = 0 (p-14)(p+11) p = 14 s = 77

*November 21, 2016*

**science**

work = force * distance

*November 21, 2016*

**Math**

2,47

*November 21, 2016*

**Math algebra**

If the quicker person takes x hours, then the slower person takes 3x hours. 1/x + 1/3x = 1/4 12+4=3x x = 16/3 so, 3x = 16 hours for the slowpoke.

*November 21, 2016*

**Math**

looks good to me

*November 21, 2016*

**Chemistry 20**

Zn + CuSO4 = Cu + ZnSO4 same number of moles of each

*November 21, 2016*

**Math**

since column 1 is the one-times column, the row must be 4.

*November 21, 2016*

**Physics**

(a) v^2 = 2.5^2 + 4.5^2 (b) 2.5 (c) 4.5

*November 21, 2016*

**Maths help asap please.**

think: (a+1)^2 = a^2+2a+1

*November 21, 2016*

**math**

the + or - status does not matter. Just find the rule as usual.

*November 21, 2016*

**maths**

t = u+2 (10t+u) + (10u+t) = 88

*November 21, 2016*

**Physics**

well, 5min = 1/12 hr. Now use the hint.

*November 21, 2016*

**Algebra pt. 2**

That's better, but express them a as pair of coordinates. (12,4) not just 12 4.

*November 21, 2016*

**maths**

x+24 + 10 = 3(x+10)

*November 21, 2016*

**Algebra**

NO Take each point and double its coordinates. Stop trying to get rid of the coordinates. The problem says to come up with a new list of coordinates for the expanded diagram. (6,2) becomes (12,4)

*November 21, 2016*

**Algebra**

No, you multiply each coordinate by the scale factor: 2 That's what the scale factor is for. what can it possibly mean to multiply x-values by y-values? You are trying to convert a point into a number. Bogus...

*November 21, 2016*

**mathematics**

what? reposting after just 5 minutes?

*November 21, 2016*

**maths**

well, 6 = 72/12, so ...

*November 21, 2016*

**Mathematics**

Let the ages of France, Emma, Father be x,y,z. Then we have x = 2y x+y = z-12 z=30 So, start substituting till you can find y.

*November 21, 2016*

**Algebar**

you have a difference of two squares a^2-b^2 = (a-b)(a+b) where a = 9x^3 b = 5y^5 Now just plug and chug.

*November 21, 2016*

**math**

chain rule: (a) 4(x^2+1)^3 * 2x (b) not sure what you mean by "primitive" The extrema (max and min) can be found where 8x(x^2+1)^3 = 0

*November 21, 2016*

**maths**

22.5

*November 21, 2016*

**Math**

x-21 = 71-x

*November 21, 2016*

**motion**

Take a look at this example. It is very similar to yours. http://www.a-levelmathstutor.com/m-momimp-coeffrest.php

*November 21, 2016*

**Math, Surds @Reiny got it**

My bad. I read "diagonal" not "area"

*November 21, 2016*

**Math, Surds**

s = 60/?2 = 30?2 m well, a square has 4 sides, so ...

*November 21, 2016*

**math**

m-1/m ... what? I will say, however, that (m-1)^2/m^2 = ((m-1)/m)^2 (m^2-1)/m^2 = (m-1)(m+1)/m = (m-1)/m * (m+1)

*November 21, 2016*

**Chemistry**

Looks like 205g to me.

*November 21, 2016*

**Maths**

My bad. I should have said that when ?=1 we get the equation x^2 + y^2 +4x - 3 + 1(2x^2 + 2y^2 +4x -6y + 3) = 0 3x^2+8x + 3y^2-6y = 0 (x + 4/3)^2 + (y-1)^2 = 25/9 Now the three circles can all be seen to intersect at the same two points: http://www.wolframalpha.com/input/?i=...

*November 21, 2016*

**Maths**

When ?=1, we get the circle (x+2)^2 + (y-1)^2 = 5 The three circles can be seen at http://www.wolframalpha.com/input/?i=plot+x%5E2+%2B+y%5E2+%2B4x+-+3+%3D+0,+++2x%5E2+%2B+2y%5E2+%2B4x+-6y+%2B+3+%3D0,+(x%2B2)%5E2+%2B+(y-1)%5E2+%3D+5,+y%3D0,+x%3D0

*November 21, 2016*

**Maths**

Solving the system of equations x^2 + y^2 +4x - 3 = 0 2x^2 + 2y^2 +4x -6y + 3 =0 Is the same as solving the system x^2 + y^2 +4x - 3 = 0 ?(2x^2 + 2y^2 +4x -6y + 3) = 0 The equation x^2 + y^2 +4x - 3 + ?(2x^2 + 2y^2 +4x -6y + 3) = 0 can be written as (*) (1+2?)x^2 + 4(1+2?)x...

*November 21, 2016*

**math-mechanics 1**

(a) v = 2i (b) r = 2it + (-0.2i+.05j)t^2 (c) we want r to have a zero i component. So, 2t - 0.2t^2 = 0 0.2t (10-t) = 0 t=10 (d) v = 2i + (-.4i+.1j)t we want the i and j components to be equal, so 2-.4t = .1t 2 = .5t t = 4

*November 21, 2016*

**Math**

If the tree's height is x meters, the broken tree forms a right triangle with sides 12/25 x and 10. The hypotenuse is 13/25 x. 10^2 + (.48x)^2 = (.52x)^2 Now just solve for x.

*November 21, 2016*

**Math**

well, how many months in 4 years? 423 each month...

*November 21, 2016*

**algebra 1**

x = 7y/4 + 3/4 y = 4x/7 + 3/7 x = -3y/4 - 7/4 y = -4x/3 - 7/3

*November 20, 2016*

**MATH**

:DDDDDDDDDDDDDDD

*November 20, 2016*

**MATH**

So to restate it in this account that I have been asking the questions and was granted your help. Oh wow that is interesting Ms. Sue and I want to do that with my life also, but sometimes I need some light on how to do these problems. The question I got wrong was a question I ...

*November 20, 2016*

**MATH**

Sorry Ms. Sue I had logged on to my account and answered your post on that account but it was really me STEVE as Your best friend

*November 20, 2016*

**MATH**

THANKS MS. SUE I got 21/22 questions correct I HATE THAT I WANT 22/22 my mom will get really mad so I have to correct the problem I got wrong before she finds out but thank you for the help for the rest of the questions

*November 20, 2016*

**MATH**

3. (5 * 2.25) - (5 * 0.65) = 8 or $8.00 4. Thank you

*November 20, 2016*

**MATH**

1.= 3.2*10^6 NOW I JUST NEED HELP WITH QUESTIONS 3 AND 4 Thank you Ms. Sue for all of your help so far

*November 20, 2016*

**MATH**

3. THAT EQUATION DOES NOT WORK Ms. Sue IT EQUALS $9.95 AND 9.95 IS NOT AN ANSWER

*November 20, 2016*

**MATH**

1. WOW YOU DON'T KNOW, WELL I DON'T KNOW EITHER 2. (2/3) * (1/4) = 1/6 3. (5 * 2.25) - (2 * 0.65) = 9.95 4. A OR B

*November 20, 2016*

**MATH**

These are my last few question that I need help with PLEASE STAY WITH ME MS. SUE 1. In 2012, the total population of Florida was 3,158,697 people. What was the population in scientific notation, approximately? A. 3.2 * 10^5 B. 3.2 * 10^6 C. 3.2 * 10^7 D. 32 * 10^7 2. If there ...

*November 20, 2016*

**math**

rate of change is (y-change)/(x-change) For the table shown, check each section. The rates from point to point are (70-30)/(15-0) = 2 (0-70)/(23-15) = -70/8 (45-0)/(30-23) = 45/7 (60-45)/(35-30) = 3 absolute values are always positive. So, just compare the positive values ...

*November 20, 2016*

**MATH**

No she would so estimated it would be just 2 or B Sorry for the confusion Ms. Sue Thank you

*November 20, 2016*

**MATH**

3 * (7/8) = 2 5/8 yards (7/2) / (14/9) = 2 1/4 pieces Thank you Ms. Sue but I don't get you 2nd equation It equals 2 1/4 but that is not an answer choice

*November 20, 2016*

**MATH**

1. Serena has 7/8 yd of fabric. To complete her craft project, she needs 3 times that amount. How many yards of fabric does Serena need? A. 2 5/8 B. 2 7/8 C. 3 3/7 D. 3 7/8 2. A length of ribbon is 3 1/2 yd long. How many pieaces 1 5/9 yd long can Joy cut from the length of ...

*November 20, 2016*

**Math**

Thanks anyways.

*November 20, 2016*

**Math**

So it would Be C

*November 20, 2016*

**Math**

Thanks Ms. Sue and Reiny A. 1/3 B. 1/4 C. 1/2 D. 1/8

*November 20, 2016*

**Math**

Or 1/2

*November 20, 2016*

**Math**

it = 0.5

*November 20, 2016*

**Math **

1. Ms. Johnson’s class is having a pizza party. If there are 14 students and 7 pizzas cut into 8 slices, what answer choice represents the fraction of one pizza that each student receives? If someone can give me an equation to solve to get the answer for this. Or Help me ...

*November 20, 2016*

**Math**

1. What is 0.68 written as a simplified fraction?

*November 20, 2016*

**Math**

32-19=13 32+19=51

*November 20, 2016*

**Math**

(x+3)/2 >= (2-x)/-2 x+3 >= x-2 3 >= -2 true for any x

*November 20, 2016*

**math**

So, b-c = 10/4 b+c = 5

*November 20, 2016*

**Linear Programming - The Graphical Method**

Just graph each boundary line for the constraints, then evaluate the function at each vertex.

*November 20, 2016*

**Calc III**

take a look here http://math.stackexchange.com/questions/1572835/finding-the-max-and-min-values-for-a-surface-on-region-r and I think you will be able to get going. Google can also provide many other examples.

*November 20, 2016*

**ST**

enter your data here to see the details. http://www.zweigmedia.com/RealWorld/LPGrapher/lpg.html

*November 20, 2016*

**Calculus**

work this one just like the last. But time = distance/speed, rather than cost=distance*rate.

*November 20, 2016*

**Calculus**

If the cable comes out of the river x meters from the point directly opposite the factory, then the cost is c = 3?(x^2+2000^2) + 1(4500-x) so, find where dc/dx=0 The answer is 4500-x.

*November 20, 2016*

**Math help fast**

x^2/2 - 2x = 16 ...

*November 20, 2016*

**Maths**

Find where the curves intersect. Clearly, at x=2, since y(2) = 22 = 11*2 I was wondering about the "hence". So, the area in question has two parts. That under the line and that under the curve: a = ?[0,2] 11x dx + ?[2,3.7988] 10+8x+x^2-x^3 dx = 22 + 27.2556 = 49.2556...

*November 20, 2016*

**maths**

x^2 - 8x - 20 = 0 (x-10)(x+2) = 0 ...

*November 20, 2016*

**Calculus**

x=cos^2t y=ln(sint) dy/dt = cost/sint dx/dt = -2cost sint dy/dx = dy/dt / dx/dt = (cost/sint)/(-2cost sint) = -1/2 csc^2(t) d^2y/dx^2 = d/dx(dy/dx) = d/dt (dy/dx) / dx/dt = (-csct * csct cott)/(-2cost sint) = 1/2 csc^2(t) cot(t) * sect csct = 1/2 csc^3(t)

*November 20, 2016*

**Maths**

L1 has slope 0 L2 has slope ?3 see what you can do with that.

*November 20, 2016*

**Math**

I assume you meant (5x-2)/4 + 1/2 = (3y+2)/2 (7y+3/3) = x/2 + 7/3 Cleaning things up a bit, you have 5x-6y = 4 3x-42y = -8 See what you can do with that.

*November 20, 2016*

**Math**

If it was x, then .4*x + .6*8 = 1.0*6 x = 3

*November 20, 2016*

**Math! Help asap**

interesting, since 124 = 4*31 Where did you get the 19? "over by"? Try just "over" Better yet, use real math (5+-[31])/2 Though I have never seen [] used to denote square root before.

*November 19, 2016*

**Math! Help asap**

It does not factor over the rationals, since the discriminant b^2-4ac = 100+24 = 124 is not a perfect square. Use the quadratic formula to find the roots, or maybe there's a typo.

*November 19, 2016*

**math**

http://www.jiskha.com/display.cgi?id=1479538720

*November 19, 2016*

**math**

5*2x - (4x+6x) Looks like a zero profit.

*November 19, 2016*

**algebra**

Nope. You correctly got that x-(-3) = x+3 Work y the same way.

*November 19, 2016*

**Algebra, 8th Grade mathematics**

note that x^2-1 = (x-1)(x+1) x^3-1 = (x-1)(x^2+x+1) x^4-1 = (x-1)(x^3+x^2+x+1) so, 3^251-1 = (3-1)(3^250+3^249+...+3^1+1) So your sum is just (3^251-1)/(3-1)

*November 19, 2016*

**Maths**

each minute mark is 1/60 of a circle for the minute hand: 6° So, the minute hand has gone 37*6 = 222° around. In the meantime, the hour hand, starting at 2:00 (60° along its path), has advanced another 37/60 * 1/12 = 37/720 of a circle. So, the hour hand has moved ...

*November 19, 2016*

**FUNCTIONS HELPPPPP????**

The g(x) I suggested was a last-ditch effort to come up with some function using f1,f2,f3. You repeatedly refused to specify what you meant when you said Determine an equation for this function "this function" indicates that there is some function you want to create ...

*November 19, 2016*