Tickets for a school play cost $4 for adults and $2 for students. at the end of the play, the school sold a total of 105 tickets and collected $360.
equation 1:
equation 2:

S=number of students
a=number of adults
cost=costadult+costkids
cost=4a+2s
cost=360
360=4a+2s

total tickets is 105
105=s+a

so we got

our equations are
4a+2s=360 and
a+s=105

so wto solve
multiply 2nd equation by -2 and add to first

4a+2s=360
-2a-2s=-210 +
2a+0s=150

2a=150
divide by 2
a=75

sub back
s+a=105
s+75=105
minus 75 both sides
s=30

30 student tickets and 75 adult tickets

equation 1: 4a+2s=360
equation 2: a+s=105