If a movie ticket for adults costs $4.50 and $2.00 for kids, if 45 people attended and 162.50 dollars worth of tickets were sold, how many adults and children attended?

Okay, we need two equations to solve this
(a will represent adults and k will represent kids)
a + k = 45
a = 45 - k
450a + 200k = 16250
We replace a:
450(45 - k) + 200k = 16250
20250 - 450k + 200k = 16250
-250k = -4000
25k = 400
k = 16
45 - 16 = 29
16 kids attended and 29 adults attended