Answer
A. 1 and 1
B. 9 and 5
C. When x=0, y=0, the answers are 0 and 0,
D. No
Work Step by Step
A. Set x=1, y=0. If we plug these in the first expression into $(x+y)^{2}$
We get $(1+0)^{2}$ which is 1.
If we plug these in the second expression, $x^{2}+y^{2}$
We get $1^{2}+0^{2}$, which is $1+0$, which is also $1$
B. Set x=1. y=2
If we plug these in the first expression into $(x+y)^{2}$
We get $(1+2)^{2}$ which is 9
If we plug these in the second expression, $x^{2}+y^{2}$
We get $1^{2}+2^{2} =1+4 = 5$
C. Set x=0, y=0
If we plug these in the first expression into $(x+y)^{2}$
We get $(0+0)^{2}$ which is 0
If we plug these in the second expression, $x^{2}+y^{2}$
We get $0^{2}+0^{2} =0+0 = 0$
D. No, when x=1 and y=2 they have different answers.