Step-by-step explanation
Since the expression is a + b = 2a
In order to get the expression b-a, we need to apply the following steps:
1) Subtracting -2a to both sides:
a + b -2a = 2a -2a
2) Adding like terms:
b -a = 0
In conclusion, the expression that equals b-a is 0 [OPTION C]