Add: 2x(z+x+y) and 2y(z+y+x)
The correct option is B 2x2+2y2+4xy+2yz+2zx
2x(z+x+y)+2y(z+y+x)
=2zx+2x2+2xy+2zy+2y2+2yx
=2x2+2y2+4xy+2yz+2zx
find the product:(x+y+2z) (x2+y2+4z2-xy-2yz-2zx