Question

express in a+ib form
1).i^20+(1-2i)^3
2).i^14+(2-6i)^3
3).((5+i)(7-i))/(2+i)^2

Answer 1

ur answer &
(5+i)(7-i)/(2+i)^2
=(35+2i+1)/4+4i-1
={(35+2i+1)(3-4i)}/(3+4i)(3-4i)
=105+6i+3-140-8i^2-4i/3^2-(4i)^2
=-24+2i/9+16
=-24+2i/25
=(-24/25)+(2/25)i