Question

the price for admission for concert was $9 for adults and $4 for children all together 1770 tickets were sold in the resulting revenue is $14,680 and how many children attended the concert?

Answer 1

x+y=1770
9x+4y=14680
x=1770-y
9(1770-y)+4y=14680
15930-9y+4y=14680
-5y=-1250
5y=1250
y=1250/5
y=250
children attended=250