How do you solve $x^2 + 8x + 16 = 9$ ?

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Answer 1 · 2017-02-27T06:47:19

$x=-1$ or $x=-7$

$x^2+8x+16=9$

Subtract $9$ from both sides.

$x^2+8x+7=0$

Factorise.

$x^2+7x+x+7=0$

$x(x+7)+1(x+7)=0$

$(x+1)(x+7)=0$

$x+1=0$ and $x+7=0$

$x=-1$ and $x=-7$

How do you solve x^2 + 8x + 16 = 9x^2 + 8x + 16 = 9?