Question

(4+i)^2 - (6-i)^2
write result in standard form a+bi

Answer 1

(4+i)^2 - (6-i)^2


16+8i+i^2 - (36-12i+i^2)


16+8i-1 - (36-12i-1)


16+8i-1 - 36+12i+1


-20+20i



So (4+i)^2 - (6-i)^2 = -20+20i

Answer 2

Keep in mind that \[\large i=\sqrt{-1}\] so \[\large i^2=-1\]