Antonio purchased adult and child tickets for the fair. tickets cost $29.35 for each adult and $17.45 for each child. let x represent the number of adult tickets purchased and y represent the number of child tickets purchased. write an expression to represent the total cost of the tickets antonio purchased.
a: $29.35y + $17.45x
b: $29.35x + $17.45y
c: ($29.35 + $17.45)(x + y)
d: ($29.35 - $17.45)(x + y)