Question

Решите уравнение:а)(x-2) (x+2)-x(x+5)=-8

Answer 1

$(x - 2)(x + 2) - x(x + 5) = - 8 \\ \\ {x}^{2} - 4 - x(x + 5) = - 8 \\ \\{x}^{2} - 4 - {x}^{2} - 5x = - 8 \\ \\ - 5x - 4 = - 8 \\ \\ - 5x = - 4 \\ \\ x = \frac{ - 4}{ - 5} \\ \\ x = 0.8$

Answer 2

$a) {x}^{2} - 4 - {x}^{2} - 5x = - 8 \\ - 4 - 5x = - 8 \\ - 5x = - 8 + 4 = - 4 \\ x = - 4 \div ( - 5) \\ x = 0.8$