Question

Solve: x2 - 20x + 36 = 0

Answer 1

$x^2-20x+36=0\\\\x^2-2x-18x+36=0\\\\x(x-2)-18(x-2)=0\\\\(x-2)(x-18)=0\iff x-2=0\ or\ x-18=0\\\\\boxed{x=2\ or\ x=18}$

Answer 2

$x^2 - 20x + 36 = 0 \\ x^2-2x-18x+36=0\\ x(x-2)-18(x-2)=0\\ (x-18)(x-2)=0\\ x=18 \vee x=2$