Expand the following, using suitable identities: (x+2y+4z)2
Answer:
Given (x+2y+4z)2
Using identity, (x+y+z)2=x2+y2+z2+2xy+2yz+2zx
Here, x=x,y=2y,z=4z
(x+2y+4z)2=x2+(2y)2+(4z)2+(2×x×2y)+(2×2y×4z)+(2×4z×x)
(x+2y+4z)2=x2+4y2+16z2+4xy+16yz+8xz
Expand the following, using suitable identities: 1)(3a−7b−c)2. 2)(x+2y+4z)2 [4 MARKS]