How would we write an expression to show the number c being subtracted from the sum of a and b?
 start by writing an expression for "the sum of a and b."
 now, show c being subtracted from the sum.

Sophia wrote an equation to represent the revenue of a movie theater for one day. she let x represent the number of child tickets sold and y represents the nunver of adult tickets sold. if a child ticket cost $4, an adult ticket cost $6, and the total revenue for the daybwas $420, which equation could sophia use to represent the number of chikd and adult tickets that were sold?