Question

(1+2i)(-2+i) express in the form of a+ib state value of a and b​

Answer 1

Answer:

-4-3i

Step-by-step explanation:

(1+2i)(-2+i)

=-2+i-4i+2isquare

=-4-3i. [as isquare=-1]

so the value of a=-4 and b=-3

Answer 2

Answer:

a=-4 ,b=-3

Step-by-step explanation:

(1+2i) (-2+i)

1(-2+i) +2i(-2+i)

-2+i-4i+2i^2

-2-3i-2

-4-3i

hence, a =-4

b=-3