Respuesta :
Answer:
Advance tickets cost $30; same-day tickets cost $35.
Step-by-step explanation:
Let a = the cost of an advance ticket
and s = the cost of a same-day ticket
We have two conditions:
                             (1)          a + s = 65
                             (2)     15a + 20s = 1150
Subtract a from each side of  (1)   (3)            s = 65 - a
Substitute (3) into (2) Â Â Â Â Â Â Â Â Â Â Â Â 15a + 20(65 - a) = 1150 Â
Distribute the 20               15a + 1300 - 20a  = 1150
Combine like terms                   1300 - 5a = 1150
Subtract 1300 from each side                -5a = -150
Divide each side by -5 Â Â Â Â Â Â Â Â Â Â (4) Â Â Â Â Â Â Â Â Â Â a = 30
Substitute (4) into (1) Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 30 + s = 65
Subtract 30 from each side                   s = 35
Advance tickets cost $30; same-day tickets cost $35.
Check:
(1) 30 + 35 = 65   (2) 15 × 30 + 20 × 35 = 1150
      65 = 65       450   +   700   = 1150
                             1150 = 1150