Answer:
84 different lineups are possible
Step-by-step explanation:
The order in which the songs are chosen is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

In this question:
6 musics from a set of 9. So

84 different lineups are possible
Answer:
x<40
Step-by-step explanation:
x+10<50
x+10-10<50-10
x<40
Answer:
mutiply
Step-by-step explanation: