Answer:
it is a. because x+y you can not add them because they don't have the same variable and zero is by itself so thats why it is correct
Step-by-step explanation:
0.03
x = 6
7 x = 56-14
7 x = 42
7 x/7 to remain with x only = 42
then x = 6
753.6
3.14x4²x15
r^2x15
I hope this helps you with your algebra