Consider the following sets. U = {all triangles} E = {x|x ∈ U and x is equilateral} I = {x|x ∈ U and x is isosceles} S = {x|x ∈ U and x is scalene} A = {x|x ∈ U and x is acute} O = {x|x ∈ U and x is obtuse} R = {x|x ∈ U and x is right} Which is a subset of I? E S A R

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?