Simplify $( 3 - 6 i ) ^ { 2 } - ( 3 + 6 i ) ^ { 2 }$ and write the answer in standard form.
A) 0
B) $- 72 i$
C) $18 - 72 i$
D) $18 + 72 i$
E) $6 - 24 i$

Question

Quizplus · Accepted Answer

Expanding both squares: $(3 - 6i)^2 = 9 - 36i + 36i^2$ and $(3 + 6i)^2 = 9 + 36i + 36i^2$. Since $i^2 = -1$, both expansions simplify to $9 - 36 - 36 = -72$. Subtracting the second from the first gives $0 - 0 - 72i = -72i$.

Simplify (3−6i)2−(3+6i)2( 3 - 6 i ) ^ { 2 } - ( 3 + 6 i ) ^ { 2 }(3−6i)2−(3+6i)2

Simplify $( 3 - 6 i ) ^ { 2 } - ( 3 + 6 i ) ^ { 2 }$