Question

помогите решить номер с подробным решением

Answer 1

$f(x) = (x + 4)(x - 7) \\ f( - 4) = ( - 4 + 4)( - 4 - 7) = 0 \\ f(9) = (9 + 4)(9 - 7) = 13 \times 2 = \\ = 2$
$f( - 7) = ( - 7 + 4)( - 7 - 7) = \\ - 3 \times ( - 14) = 3 \times 14 = 42 \\ f(6) = (6 + 4)(6 - 7) = 10 \times ( - 1) = \\ = - 10$