Answer:
Adding with zero: 0 + a is just a. Zero doesn’t change the value of a. (This is also true for a + 0.)
Subtracting with zero: 0 – a = –a. Use the rule for subtracting signed numbers: Change the operation from subtraction to addition and change the sign of the second number. Likewise, a – 0 = a. It doesn’t change the value of a to subtract zero from it.
Therefore, if the equation is 0 - a, then it will have a negative outcome.