Which figures have only one pair of parallel lines

How is working backward similar to solving an equation?

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?

Acompany made a profit of 75000 over a period of 6 years on an initial investment of 15000 what is the annual roi