$$A = \frac { x ^ { 2 } - 2 x + 1 } { 4 } - 1 - 8$$
$A=\frac{\left(x-7\right)\left(x+5\right)}{4}$
$x=2\sqrt{A+9}+1$
$x=-2\sqrt{A+9}+1$
$x=2\sqrt{A+9}+1$
$x=-2\sqrt{A+9}+1\text{, }A\geq -9$
