In how many ways can 5 singers be selected from 8 who came to an audition?

8 “choose” 5 = (8! / 5! x (8 - 5) ! )

8 “choose” 5 = (8! / 3! x 5!)

= (8 x 7 x 6 x 5 x 4 x 3 x 2 x 1) /
(5 x 4 x 3 x 2 x 1) /
(3 x 2 x 1)
= (8 x 7 x 6) /
(3 x 2 x 1)
= ( 7 x 4 x 2) = 56

Therefore there are 56 ways 5 singers can be selected from 8 that came to an audition.

6(2x + 5y)6 (2x) = 12x6 (5y) = 30y12x + 30y