substitution method

Question

Adult tickets to the fall play cost $8 and student tickets cost $4. The drama class sold 30 more adult tickets than student tickets to the fall play. If the class collected $840 from ticket sales, how many adult tickets were sold?

Answer 1

no, of student ticket sold =x

no. of adult ticket sold = y

 

y = x+ 30

 

8y + 4x = 840

8(x+30) +4x =840

8x +240+4x =840

12x =600

x = 50

y= 50+30=80

 

no, of student ticket sold =x = 50
no. of adult ticket sold = y =80