At the city museum, child admission is $5.40 and adult admission is $9.30. On Friday, 134 tickets were sold for a total of $957.60. How many adult tickets were sold that day?

1 answer

a + c = 134 ---> a = 134 - c

5.4a + 9.3c = 957.6
54a + 93c = 9576
18a + 31c = 3192

sub in a = (134 - c) and solve for a