This will be a 4th quadrant 3,4,5 triangle.
Sin = -3/5
Tan = -3/4
Answer:

Step-by-step explanation:
Let n = the number of prints
and C = the total cost.
At the regular price, the formula is
C = 1.45n
During the promotion, you must pay for the first nine prints: 9 × 1.45 = 13.05.
For anything over nine prints (n - 9), you must pay $13.05 plus the promotional cost of $1.10 for each print. The promotional formula is
C = 13.05 + 1.10(n - 9) {n > 9}
1. Calculate the cost of 19 prints

2. What number of the prints is a waste of money?
During the promotion, buying fewer than nine prints would be a waste of money, because you would not be taking advantage of the promotional savings.
Numbers from what we choose will be
62,63,64,65,66,67,68,69,70,....100,101,102,103,104,105,106
multiple of 5 are
65,70,75,80,85,90,95,100,105
multiples of 3 and 5
75,90,105
multiples of 3,5,9
90
At break-even C = R so we have:-
20n + 134,000 = 160n
140n = 134,000
answer = 134,000 / 140 = 957