Question

And this (4+i)(4-i)
show work so i can understand pls ;-;

Answer 1

17

Explanation:

(a+b)(a-b)=a^2-b^2

4^2 - i^2

16 - (-1)

17

i^2= -1

Answer 2

• (a+b)(a-b)=a^2-b^2

`\\ \tt\longmapsto (4+I)(4-i)`

`\\ \tt\longmapsto 4^2-i^2`

`\\ \tt\longmapsto 16+1`

`\\ \tt\longmapsto 17`