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Posted: 5/10/2004 4:09:53 PM EST
[Last Edit: 5/10/2004 4:18:50 PM EST by lvgunner777]
It has been a while since I had to do this stuff so I need some help.

How do you figure out this problem, I don't just need the answer, I need the way to find out the answer:


9(h^2) - 72h= -119
Link Posted: 5/10/2004 4:12:43 PM EST
Link Posted: 5/10/2004 4:13:02 PM EST
the two with the variables need to be subtracted -63 and divided by -119.

it comes out funny...but then again, what the hell is that 2 up there?
Link Posted: 5/10/2004 4:13:08 PM EST
[Last Edit: 5/10/2004 4:28:28 PM EST by kickmyllama]
ok lets try this again.

9h^2 -72h + 119 = 0

(3h - 7) * (3h - 17) = 0

3h-7 = 0 3h - 17 = 0

3h = 7 3h = 17

h = 7/3 h = 17/3
Link Posted: 5/10/2004 4:14:46 PM EST
[Last Edit: 5/10/2004 4:15:25 PM EST by lvgunner777]
The 2 is the first h squared.
Link Posted: 5/10/2004 4:15:23 PM EST

Originally Posted By kickmyllama:
(9h-72h)= -63h

-63h = -119
h= (-119/-63)
h = 1.88888888888



thats what i got...


but that 2 has me thinking.


is that the number of the problem in your book?!
if it is dude, its fucking everything up.
Link Posted: 5/10/2004 4:17:58 PM EST

Originally Posted By lvgunner777:
The 2 is the first h squared.



It should have been written 9(h^2) then.
Link Posted: 5/10/2004 4:25:57 PM EST
solve for zero:

9h^2-72h+119=0

I do not know how to factor that, no common multiples for 9 and 119.
Link Posted: 5/10/2004 4:29:25 PM EST
[Last Edit: 5/10/2004 4:36:28 PM EST by raven]

Originally Posted By FooBarBaz:
solve for zero:

9h^2-72h+119=0

I do not know how to factor that, no common multiples for 9 and 119.



You need to use the quadratic equation.

I got h=2.3333333

or

h=5.666666667
Link Posted: 5/10/2004 4:36:46 PM EST
[Last Edit: 5/10/2004 4:42:11 PM EST by Sniper_Wolfe]

Originally Posted By raven:

Originally Posted By FooBarBaz:
solve for zero:

9h^2-72h+119=0

I do not know how to factor that, no common multiples for 9 and 119.



You need to use the quadratic equation.



If I'm not mistaken:

-b +- (b^2-4ac)
-------------------
2a

Where the quadratic is : a^2x + bx + c = 0

Edit to say:

Note the "+-" ...this is supposed to be plus or minus. You have to do both, there are usually two answers to the equation.

Also, quadratic is no fun. When possible, just factor them.
Link Posted: 5/10/2004 4:40:12 PM EST
9h^2 - 72h= -119
9h^2-72h+119=0
(3h-17)(3h-7)=0

3h-17=0 3h-7=0
3h=17 3h=7
h=17/3 h=7/3

Link Posted: 5/10/2004 4:42:12 PM EST
Yep, solve for zero.

Either factor it or use the quadratic formula.

9h^2 - 72h + 119 = 0

AH HAH! It factors

(3h - 7) (3h - 17) = 0

3h - 7=0 or 3h - 17 = 0
3h=7 3h=17
h=7/3 h=17/3


I hope I did all that right... I know that is the answer with factoring. Let me try the quadratic formula.

72 +/- square root of 72-4(9)(119) divided by 2(9)

72 +/- squre root of 900 divided by 18

72 +/- 30... divided by 18

102/18 or 42/18
reduced to
17/3 or 7/3


So those are your two answers 17/3 and 7/3.

Hope you can understand my notes.
Link Posted: 5/10/2004 4:50:20 PM EST
Link Posted: 5/10/2004 4:50:56 PM EST
h=2 1/3 & h=5 2/3
Link Posted: 5/10/2004 4:52:24 PM EST
[Last Edit: 5/10/2004 4:53:20 PM EST by Defcon]
You can solve it by factoring it into 2 binomials or you can use the quadratic formula.


Dang, Cypher214 nailed it. See what happens when you talk on the phone.

Link Posted: 5/10/2004 5:04:01 PM EST
Link Posted: 5/10/2004 5:11:55 PM EST
Thanks guys, I'm trying to help my little brother out on his homework and I'll be damned if he stumped me on that one. Thanks again!!!!!
Link Posted: 5/10/2004 6:45:14 PM EST
A more interesting problem is solving:
AX^3 +BX^2 + CX +D = 0

or
AX^4 + BX^3 + CX^2 + DX + E = 0

In attempting to find a general solution to the 5 order polynomials, Galois invented a who new field of mathematics...(and in the process proved that a general solution to the 5th order polynomial is impossible)

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