(x+2y+4z)2
We have, (a+b+c)2=a2+b2+c2+2ab+2bc+2ca
Applying the above formula, we get
[Here, a=x,b=2y,c=4z]
(x+2y+4z)2=(x)2+(2y)2+(4z)2+(2×x×2y)+(2×2y×4z)+(2×4z×x)
=x2+4y2+16z2+4xy+16yz+8xz
Expand the following, using suitable identities: (x+2y+4z)2