Answer:
(a)
Photo Lab Cost = 3.20 + 0.08X
Specialty Photos Cost  = 2.60 + 0.10X
(b) 30 prints is the number of prints needed for both costs to be the same
Step-by-step explanation:
Let X be the number of prints processed. Â Noting that 8 cents is $0.08 and 10 cents is $0.10,
- For Photo Lab, the equation for cost will be 3.20 + 0.08X
- For Specialty Photos, the cost will be 2.60 + 0.10X
In order for both cost to be the same set both cost equations equal(break-even point)
2.60 + 0.10X = 3.20 + 0.08X
0.10X -0.08X = 3.20 -2.60
0.02X = 0.60
or
X = 0.60/0.02 = 30 prints
At prints developing photos at both shops will be the same and can be found by substituting for X in either equation
2.60 + 0.1(30) = 2.60 + Â = $5.60
Note
To get 30 prints you need at least 2 rolls since there are only 24 prints. per roll The second roll needs only 6 prints developed and you cannot develop 6/24th of a roll but the whole roll. Â However, I read the question as the number of prints from each shop to break even in cost.