Help with this equation?

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Hanajima

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I got that answer by finding a common denominator for all parts of the problem which was (x+8)(x-4)

I then got:

x^2+ 8x - 2x - 8 = 15

So i turned that into a quadratic and got:

x^2 + 6x -23 =0

I'm not sure if I'm using the proper method to solve this or if I'm totally on the wrong track.
Any help would be appreciated, thanks!
 
Hanajima said:


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I got that answer by finding a common denominator for all parts of the problem which was (x+8)(x-4)

I then got:

x^2+ 8x - 2x + 8 = 15 <<< That should be positive
So i turned that into a quadratic and got:

x^2 + 6x -7 =0

(x+7)(x-1) = 0


I'm not sure if I'm using the proper method to solve this or if I'm totally on the wrong track.
Any help would be appreciated, thanks!
Click to expand...
 


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Sorry guys..another question.

For #35:

I got a common denominator of 5n for both sides, and then it looked like this:

(5)n/5n - 3(5)/5n = 22(n)/5

Then I cleaned that up and got:

5n - 15 = 22n

I turned that into:

17x - 15 = 0

x = 0.8823529412

It this right :? ?

For #36:

I got a common denominator of (x+3)(x-7) for both sides, when I got everything sorted out it looked like:

(x^2-7x) - (2x^2 + 8x +42) = 6x + 18

From there I combined like terms and set that equation to 0 which looked like:

-x^2 - x +24 = 0

I get 4.424428901, -5.424428901 for my possibe xs but it says it's incorrect
 
Hanajima said:


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Sorry guys..another question.

For #35:

I got a common denominator of 5n for both sides, <<<< Correct and then it looked like this:

(5)n/5n - 3(5)/5n = 22(n)/5 <<< Incorrect

n * (5n) - 3/n * (5n) = 22/5 * (5n)

5n[sup:1rf5zodk]2[/sup:1rf5zodk] - 15 = 22n

Now continue.....

Then I cleaned that up and got:

5n - 15 = 22n

I turned that into:

17x - 15 = 0

x = 0.8823529412

It this right :? ?

For #36:

I got a common denominator of (x+3)(x-7) for both sides, when I got everything sorted out it looked like:

(x^2-7x) - (2x^2 + 8x +42) = 6x + 18

From there I combined like terms and set that equation to 0 which looked like:

-x^2 - x +24 = 0

I get 4.424428901, -5.424428901 for my possibe xs but it says it's incorrect
Click to expand...
 
Hanajima said:
For #36:
I got a common denominator of (x+3)(x-7) for both sides, when I got everything sorted out it looked like:
(x^2-7x) - (2x^2 + 8x +42) = 6x + 18
From there I combined like terms and set that equation to 0 which looked like:
-x^2 - x +24 = 0
I get 4.424428901, -5.424428901 for my possibe xs but it says it's incorrect
Click to expand...
Close...should be:
-x^2 - 5x + 24 = 0
Yer smart nuff to redo and find your error!!
 
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