Can someone help me with these questions im bad at math

1. 3(x+2)
3(3+2)
9+6
=15

2. 3x+2
3(3)+2
9+2
=11

3. they are not equivalent expressions because one equals 15 and one equals 11.

There is no graph but what i can say is that 1 is the slope and that -2 is the y- intercept