Answers:
Biggest = 100 inches
Smallest = 31 inches
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Work Shown:
Replace d with 132 to get,
Tmax = 3d/4 + 1
Tmax = 3*132/4 + 1
Tmax = 396/4 + 1
Tmax = 99 + 1
Tmax = 100
The biggest size they should buy is a 100 inch tv.
Do the same for the minimum size equation.
Tmin = d/4 - 2
Tmin = 132/4 - 2
Tmin = 33 - 2
Tmin = 31
The smallest tv they should buy is a 31 inch tv.