Question

which of the following are linear equations of the variable? (a) x+y+7=12

Answer 1

I didn't understand the question. Anyway I am telling you how to solve it.
x+y+7=12
12-7=5
So the answer will be 3+2+7=12
Please forgive if this is not the one you asked.

Answer 2

x+y+7=12
x+y=12-7
x+y=5
x+y-5=0