Question

А(а+2б)-(а+б) ^2 (x-2)(x+4)-2x(1+x)

Answer 1

$a(a + 2b) - {(a + b)}^{2} = {a}^{2} + 2ab - {a}^{2} - 2ab - {b}^{2} = - {b}^{2}$

$(x - 2)(x + 4) - 2x(1 + x) = {x}^{2} - 2x + 4x - 8 - 2x - 2 {x}^{2} = - {x}^{2} - 8$