SOLUTION: |x-9|=x^2-9x

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Question 720340: |x-9|=x^2-9x
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
|x-9|=x^2-9x
solve for 2 possibilities:
for (x-9)>0
x-9=x^2-9x
x^2-10x+9=0
(x-9)(x-1)=0
x=9
or
x=1
..
for (x-9)<0
-x+9=x^2-9x
x^2-8x-9=0
(x-9)(x+1)=0
x=9
or
x=-1
Check:
for x=9
|x-9|=x^2-9x
0=81-81
0=0 (x=9 ok)
..
for x=1
|x-9|=x^2-9x
|1-9|=1-9
8≠-8 (reject x=1)
..
for x=-1
|x-9|=x^2-9x
|-1-9|=x^2-9x
10=10 (x=-1 ok)
solution: x=9,-1