(5х+2х)-2,5х(8х+7) при х=-2

Question

(5х+2х)-2,5х(8х+7) при х=-2

Answer 1

7x-2,5x(8x+7)=7x-2,5x ×8x-2,5x×7=7x-20x-17,5x=-30,5x
x=-2 => -30,5×(-2)=61
ответ 61