Question

6.05]An auditorium earned $30,000 in sold−out concert ticket sales. Front section tickets cost $75 per seat and back section tickets cost $50 per seat. The number of front section seats is twice the number of back section seats. How many seats are in the front section?

Answer 1

you form 2 equations
let x be number front seats and y number back seats:
x = 2y
75x + 50y = 30,000
substitute for x in second equation:
75(2y) + 50y = 30000
200y = 30000
y = 150
and x = 2y = 300

there are 300 seats in the front section