Question

Tickets to a concert cost 2$ for children and 5$ for adults. If 630 people attended the concert and ticket sales totaled 2,910$, how many children attended the concert

Answer 1

Look I only searched the answer but here it is.
80 childrens tickets and 550 adults tickets were sold.

Answer 2

c= children

a= adults

c+a = 630

c=630-a

2c + 5a = 2910

2(630-a) +5a=2910

1260-2a+5a=2910

1260+3a=2910

3a=1650

a = 1650/3=550

550 adult tickets

630-550 = 80 children's tickets

check:

550*5 = 2750

80*2=160

2750+160=2910