Question

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (–1 + i) + (21 + 5i)?
(–1 + i) + (21 + 5i) + 0
–1 + (i + 21) + 5i
(–1 + 21) + (i + 5i)
–(1 – i) + (21 + 5i)

Answer 1

(–1 + 21) + (i + 5i)

Reason: the commutative property lets you reorder terms so you can group the real parts (−1 and 21) and the imaginary parts (i and 5i) together.