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-9x+15=3(2-x)

-9x+15=6-3x

-9x+9=-3

my answer key is tellng me 9 should become negative, why?

-6x-9

x= \(\frac{-9}{-6} or- \frac{3}{2}\) but im still confused on why 9 becomes negative

 Oct 6, 2022
 #1
avatar+1015 
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-9x + 15 = 3(2-x)

Distribute => -9x + 15 = 6 - 3x

Add 9x to both sides => 15 = 6 + (-3 + 9)x

Subtract 6 and distribute => 9 = 6x 

x = 3/2

If you subtract 15 from both sides, yes you get -9 because 6 - 15 = -9, but if you subtract 6 from both sides, you get positive 9 on the other side. Combining like terms can give negative numbers.

 Oct 6, 2022

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