Answer:
Addition property of equality
Step-by-step explanation:
To solve the equation a - 3 = 1, we need to isolate the variable, which is a to solve the equation.
Since we have constant term on LHS (left hand side), i.e., -3, we need to cancel it out so that we can isolate a.
To cancel it out simply add its inverse to both sides, which is 3.
So,
a - 3 + 3 = 1 + 3
a = 4
Since we added a positive number to both sides, we used addition property of equality to solve for a.
