SOLUTION: What is the solution set of the equation? 3x-9 -3x ----- = ---- x-3 2 When I worked this problem out, I got {-3, 2} But the answer is {-2} I don't under

Algebra ->  Rational-functions -> SOLUTION: What is the solution set of the equation? 3x-9 -3x ----- = ---- x-3 2 When I worked this problem out, I got {-3, 2} But the answer is {-2} I don't under      Log On


   



Question 592763: What is the solution set of the equation?
3x-9 -3x
----- = ----
x-3 2
When I worked this problem out, I got {-3, 2}
But the answer is {-2} I don't understand how they got that.
My work:
3x-9 *(2) = -3x * x-3
---- -----
x-3 2
6x -18 -3x^2 +9x
------- = -----------
(x-3)(2) (2)(x-3)
(Subtract 6x -18 to get it on one side.)
-3x^2 +9x -6x -18
----------------- SIGN ERROR S/B +18
(x-3)(2)
Combine like terms
-3x^2 +3x -18
---------------
(x-3)(2)
(Factor)
(-3)(-18) =54
-3x^2 -6x +9x-18
----------------
(x-3)(2)

3x(x-2) 9(x-2)
(3x+9)(x-2)
3x+9=0
-9 -9
3x=-9
/3 /3
x=-3
x-2=0
+2
x=2

I really don't understand how to solve this.



Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


You went to way more trouble than was necessary, and then made algebra errors in the process. See annotation in your problem statement. If you take it from there, it works out correctly. However, it would have been much easier had you first factored the LHS numerator:







Solve from there.

John

My calculator said it, I believe it, that settles it
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