Question

Solve √(9x+81)=x+5
The solution is x=

Answer 1

is it -8,7 and do I put parenthesis around them

Answer 2

Square both sides:\[9x+81 = (x+5)^{2}\]\[9x+81 = x^{2}+10x+25\]Get everything on one side:\[0 = x^{2}+x-56\]Factor:\[0 = (x-7)(x+8)\]So x is 7 or -8

Answer 3

x=7

Answer 4

7(9)+81=63+81=144
7+5=12
7 works
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9(-8)+81=9
-8+5=-3
-8 doesn't work
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:)
Great work!