Mathematics 101

Question

Find the product of 3 + i and 3 – i.

Select one:

9

8

10

5

Answer 1

Correct option is (c) 10

To find the product of (3 + i) and (3 - i), we can use the FOIL method, which stands for First, Outer, Inner, Last.

(3 + i) x (3 - i) = 3 x 3 + 3 x (-i) + i x 3 + i x (-i)

Simplifying the product using the fact that i² = -1, we get:

(3 + i) x (3 - i) = 9 - i² 

= 9 - (-1)

= 9 + 1

= 10

Therefore, the product of (3 + i) and (3 - i) is 10.