\[x^{2} - 12x + 35 =\]
\[= x^{2} - 12x + 36 - 1 =\]
\[= (x - 6)^{2} - 1^{2} =\]
\[= (x - 6 - 1)(x - 6 + 1) =\]
\[= (x - 7)(x + 5).\]