Question

Express the following in the form of a+ib,

a, b∈R i = −1. State the values of a and b.

i) (2+i)

(3−i) (1+2i)​

Answer 1

Answer:

I) (2+i)(3-i)(1+2i)

=(2+i)(3-i+6i-2isquare)

=(2+i)(3+5i+2)

=(2+i)(5+5i)

=(10+5i+10i+5isquare)

=(15+15i)

=15(1+i)