Question

упростите:
2x(z+x+y)+2b(b-x-y)-2y(x-c-y)​

Answer 1

$\displaystyle 2x(z+x+y)+2b(b-x-y)-2y(x-c-y)=\\ 2xz+2x^2+2xy+2b^2-2bx-2by-2xy+2cy+2y^2=\\ 2xz+2x^2+2b^2-2bx-2by+2cy+2y^2$