yee
c=number of children tickets
a=number of adult tickets
131 tickets sold means c+a=131
total is 1050.40 so 5.90c+9.60a=1050.40
elimination
for c+a=131
multily both sides by -5.90
-5.90c-5.90a=-772.9
add that to other equation
-5.90c-5.90a=-772.9
5.90c+9.60a=1050.40 +
0c+3.70a=277.5
3.70a=277.5
divide both sides by 3.7
a=75
sub into other one
c+a=131
c+75=131
minus 75 from both sides
c=56
56 child tickets were sold that day
