Question

ME AJUDEM POR FAVORRRRR

Answer 1

$a {x}^{2} - a {y}^{2} + b {x}^{2} - b {y}^{2} = \\ = a( {x}^{2} - {y}^{2} ) + b( {x}^{2} - {y}^{2} ) = \\ = a(x + y)(x - y) + b(x + y)(x - y) = \\ = a \times 5 \times ( - 3) + b \times 5 \times ( - 3) = \\ = - 15a - 15b = - 15(a + b) = \\ = - 15 \times 6 = - 90$