Math ! 1. betty, dawnie, and joan share the same birthday. they’ve decided to join together to have one big birthday party. the event location says it will cost $80 for the rental of the space and $10 per guest. each girl invites x number of guests, including themselves in their guest count. the girls have each written a different expression to represent the total cost of the party. explain how each expression represents the final cost. (a) betty’s expression: 10x + 10x + 10x + 80 (b) dawnie’s expression: 10(x + x + x) + 80 (c) joan’s expression: x(10 + 10 + 10) + 80