How many students and how many adults bought tickets?

Question

The spring concert at a certain high school sold 150 tickets. Students were charged ​$3 each and adults ​$7 each. The income from the sale of tickets was ​$786. How many students and how many adults bought tickets?

Answer 1

S + A = 150

multiply by 3

3S +3A = 150

3S + 7A = 786

3S + 3A = 450

subtract to get

4A =336

A =336/4 = 84 adults

S = 150-84 = 66 students

3(66) + 7(84) = 198 + 588 = 786