Question

2. If x=3.y = 1 and z.-4. find the value of each of the following expressions
(1) x2 + y2 + z2 + 2xy + 2yz +2 zx​

Answer 1

x2+ 2xy+y2 + z2 +2yz+ 2zx
(X+y)2+ 1 + 2.1.-4+2.-4.3
(3+1)2+1-8-24
16+1-8-24
-15