Question

Suppose a - b = 0 which expression equals a + b?
a. o
b. -2b
c. -b^2
d. a/b
e. 2a

Answer 1

Hello from MrBillDoesMath!

Answer:

Choice e  (2a)

Discussion:

a - b = 0   =>  a = b    (*)

So

a + b  = (b) + a             => commutative property and b = a from (*)

         = (a)  + a        

          = 2a

which is Choice e.

Thank you,

MrB