Answer: p^2 + 4q^2 + r^2 + 4pq + 4qr + 2pr
Explanation:
We need to expand (p+2q+r)^2
We know that (x+y+z) ^2 = x^2 + y^2 + z^2 + 2xy + 2yz + 2xz
Here x = p,y = 2q and z = r
Therefore (p+2q+r)^2 = (p)^2 + (2q)^2 + (r)^2 + 2(p)(2q) + 2(2q)(r) + 2(p)(r)
= p^2 + 4q^2 + r^2 + 4pq + 4qr + 2pr
