Question

(7x+8y)-(5x-2y) при x= -3/4,y=0,025

Answer 1

(7x+8y)-(5x-2y) = 7x+8y-5x+2y = 2x+10y = 2*(-0,75)+10*0,025= -1,5 + 0,25= -1,25

Answer 2

$(7x+8y)-(5x-2y)= \\=7x+8y-5x+ 2y=\\ = (7x-5x)-(8y+2y) = \\ = {boldsymbol{2x +10y}} \ \ \ boxed{x = - frac{3}{4} = 75% = -0,75; \ \ \ } \ \ boxed{y=0,025} \ \ {boldsymbol{2(-0,75) + 10(0,025)} = {boldsymbol{-1,5 + 0,25} = {boldsymbol{-1,25;}$

$boxed{boldsymbol{OTBET:-1,25}}$