H e e e e l l l p

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

See attachment below and find the equivalent of tan(∠qsr)

Aschool allots ? 1500 to spend on a trip to the theatre. theatre tickets have a regular cost of ? 55 each and are on offer for 1 5 off. a train ticket for the day will cost ? 12 each. if 2 teachers and the maximum number of students attend, how much money will the school have left over?