Question

Помогите решить пожалуйста

Answer 1

(2х-y)-5x(x-2y)+(x-y)(x+y)=2x-y-5x^2+10xy+x^2+xy-yx-y^2=2x-y-4x^2+10xy-y^2=2*(1/3)+2,5-4*((1/3)^2+10*(1/3)*(-2,5)-((-2,5)^2)=0,6+2,5-0,36-7,5-6.25=-11.01