Question

How do you evaluate `( 3- 2i ) ( 4+ i)`?

Answer 1

`14-5i`

Explanation:

`(3-2i)(4+i)`

`(3)(4)+(3)(i)-(4)(2i)-(2i)(i)`

`12 + 3i -8i-2i^2`

`i^2= sqrt(-1)*sqrt(-1)=-1`

`12 + 3i -8i-2(-1)=14-5i`

The multiplication is exactly the same as for multiplying any brackets. You just collect like terms, but you have to remember that `i xx i = -1`