Question

упростите : а)(2х^2-хy+y^2)-(х^2-2хy-y^2)
б)5(х-3)-4(2-х).
Плиз

Answer 1

$(2x^2-xy+y^2)-(x^2-2xy-y^2) =2x^2-xy+y^2-x^2+2xy+y^2= \ =2x^2-x^2-xy+2xy+y^2+y^2=x^2+xy+2y^2 \ \ 5(x-3)-4(2-x)=5x-15-8+4x=5x+4x-15-8=9x-23$