[tex] {(a + 12)}^{2} +( a + 12) = (a +1 2)(a + 12 + 1) = (a + 12)(a + 13)[/tex]
[tex]2(y - 7) + {(y - 7)}^{2} =( y - 7)(2 + y - 7) = (y - 7)(y - 5)[/tex]
[tex] {(a + b)}^{3} - {(a + b)}^{2} = {(a + b)}^{2}(a + b - 1)[/tex]
[tex]x(x + 7) - 3 {(x + 7)}^{2} = (x + 7)(x - 3(x + 7)) = (x + 7)( - 2x - 21) [/tex]