Question 1204764
a = number of adult tickets
c = number of child tickets.
your equations are:
a + c = 200
9a + 5c = 1420
multiply boh sides of the first equation by 9 and leave the second equation as is to get:
9a + 9c = 1800
9a + 5c = 1420
subtract the second equation from the first to get:
4c = 380
solve for c to get:
c = 380/4 = 95
a = 200 - 95 = 105
you have 105 adult tickets and 95 child tickets.
total cost is 9 * 105 + 5 * 95 = 1420.
numbers look good.
your solution is 105 adult and 95 child tickets were sold.