Answer:
The length of the case is 17 inches.
Step-by-step explanation:
A flute case is shaped like a rectangular prism with dimensions:
height = 5 inches;
width = 3 inches;
length = x inches.
The volume of the case is 255 cubic inches.
Use formula for the volume of the rectangular prism:
Thus,
The length of the case is 17 inches.