Question

СРОЧНО СРОЧНО СРОЧНО СРОЧНО​

Answer 1

$a \times b = (3x - 5)(7x + 1) = 21 {x}^{2} + 3x - 35x - 5 = 21 {x}^{2} - 32x - 5$

$m \times n = 4x \times 5x = 20 {x}^{2}$

$a \times b - m \times n = 21 {x}^{2} - 32x - 5 - 20 {x}^{2} = {x}^{2} - 32x - 5$

если х = 2, то

${2}^{2} - 32 \times 2 - 5 = 4 - 64 - 5 = - 65$