Question

Suppose a - b = 0Which one of these expressions equals ab?

A. 2a
B. 0
C. b^2
D. 2b
E. a/b

Answer 1

If a-b=0, a=b, so ab=bb=b^2

Answer 2

b^2

Explanation:

a - b = 0

Add b to each side

a-b+b = 0+b

a=b

We want to find ab

Replace a with b

b*b

b^2