Erica spent $115 on school she actually spent $82.50 what is erica's percent of error

Name the most appropriate metric unit for each measurement

Solve: 3x+y=6 4x-2y=18 show all work !

At a soccer tournament 1212 teams are wearing red shirts, 66 teams are wearing blue shirts, 44 teams are wearing orange shirts, and 22 teams are wearing white shirts. for every 22 teams at the tournament, there is 1 team wearing shirts. choose 1