55+added=133
added=amount addeed per week times 6=6x
55+6x=133
minus 55 both sides
6x=78
divide both sides by 6
x=13
add 13 per week
y=13x+55
Answer:
The Answer is that Senior Citizen Tickets cost: $4 and Child tickets cost: $7.
Step-by-step explanation:
Let s = the cost of senior citizen tickets
Let c = the cost of child tickets
The number of tickets sold for each type added together equals the sales for each day. Equations below:
Day 1
3s + 9c = $75
Solve for s:
3s = 75 - 9c
s = 25 - 3c
Day 2
8s + 5c = $67
By substitution:
8(25 - 3c) + 5c = 67
200 - 24c + 5c = 67
-19c = -133
c = -133 / -19 = $7 cost for child tickets.
Solve for s:
s = 25 - 3c
s = 25 - 3(7)
s = 25 - 21 = $4 cost for senior citizen tickets.
Proofs:
Day 1
3s + 9c = $75
3(4) + 9(7) = 75
12 + 63 = 75
75 = 75
Day 2
8s + 5c = $67
8(4) + 5(7) = 67
32 + 35 = 67
67 = 67
Answer: 9x2 + 15x -6
Step-by-step explanation: ( 3x + 6) (3x -1)
9x2 - 3x + 18x - 6
= 9x2 + 15x -6