Answer:
x = 1, y = -2
Step-by-step explanation:
15x + 3y = 9 (1)
10x + 7y = -4 (2)
3 × (2) - 2 × (1)
3 × (2)
30x + 21y = -12 (3)
2 × (1)
30x + 6y = 18 (4)
(3) - (4)
15y = -30
y = -30 / 15
y = -2
sub y = -2 into (1)
15x + 3y = 9
15x + (3 × -2) = 9
15x - 6 = 9
15x = 9 + 6
15x = 15
x = 15 / 15
x = 1
Answer:
24 premium tickets were sold.
Step-by-step explanation:
Let :
Deluxe ticket = x
Regular tickets = x + 78
Premium tickets = y
x + (x + 78) + y = 208
4x + 2(x+78) + 10y = 714
2x + y = 208 - 78
4x + 2x + 156 + 10y = 714
2x + y = 130 - - - - - (1)
6x + 10y = 558 - - - - (2)
Now we can solve the simultaneous equation using elimination method :
From (1)
y = 130 - 2x
Put y = 130 - 2x in (2)
6x + 10(130 - 2x) = 558
6x + 1300 - 20x = 558
- 14x = 558 - 1300
-14x = - 742
x = 742 / 14
x = 53
Put x = 53 in y = 130 - 2x
y = 130 - 2(53)
y = 130 - 106
y = 24
