Which are the solutions to $x^2+9x=36$ ?

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Answer 1 · 2016-12-08T05:23:14

$x=-12$
$x=3$

$x^2+9x=36$

Subtract 36 from each side:
$x^2+9x-36=0$

Two numbers that multiply to $-36$ and add to $9$ are: $-3$ and $12$

$x^2-3x+12x-36=0$

$x(x-3)+12(x-3)=0$

$(x+12)(x-3)=0$

$x=-12$
$x=3$

Which are the solutions to x^2+9x=36x^2+9x=36?