At a certain theater 4 adult tickets and 2 children's tickets cost $36.50. Three adult tickets and 5 children's tickets cost $38.75. Which
system of equations could be used to determine the cost of one adult
ticket, a, and one child's ticket, c?
A. 4a +2c= 36.50
3a + 5c = 38.75
B. 7a+ 7 = 14
a+b= 75.2
C. 7a = 36.50
5a + 7c = 38.75
D. 4a + 2c = 38.75
За + 5c = 36.50