Question

1 - (- а + 4)(9 - а) - (а + 3)(а - 5), при а = - 10

Answer 1

$1 - 14 \times 19 - ( - 7) \times ( - 15) = 1 - 266 + 7 \times ( - 15) = 1 - 266 - 105 = - 370$