(2 + 5i)2 − 20i +1, (4 + i)(-4 + i) ÷ 17, (3 + 2i)2 − (2 + 3i)2, 2i(5 + 4i) − 5(3 + 2i), (-2i)4 + (3i)3 + (27i) Solutions: -1, 10, -20, 16

Question

match the expressions with their solutions

Answer 1

Expand each expression:

(a) 5-10i=5(1-2i); (b) -17/17=-1; (c) 2-2i=2(1-i); (d) 10i-8-15-10i=-23; (e) -8i+9i+27i=28i.

There are 5 expressions and only 4 solutions, the second expression (b) matches the first solution.