10X- 5x- 3x= 0 the solution set is

Two cyclists 84 miles apart start riding toward each other at the same. one cycles 2 times as fast as the other. if they meet 4 hours later, what is the speed (in mi/h) of the faster cyclist?

Kelli swam upstream for some distance in a hour. she then swam downstream the same river for the same distance in only 6 minutes. if the river flows at 5km/hr, how fast can kelli swim in still water?

15. jiovanni is looking in to two different companies that offer study guides for math exams. test prep 101 charges a $5 flat fee and an additional $0.25 per problem. math charges a $2 flat fee and an additional $0.50 per problem. how many prablems would make the costs of the two companies be equal? varibles: equations/eniqualities{ {