第1421题：复数的加减法则
计算 (5+6i)(5+6\mathrm{i})(5+6i) +(−2−2i)+(-2-2\mathrm{i})+(−2−2i) −(3−4i)=?-(3-4\mathrm{i}) =?−(3−4i)=?
A. 3+8i3+8\mathrm{i}3+8i
B. 3−8i3-8\mathrm{i}3−8i
C. 8i8\mathrm{i}8i
D. −8i-8\mathrm{i}−8i
