Answer:
The length of the shortest piece is 11 inches. The length of the medium piece is 14 inches. The length of the longest piece is 20 inches.
Explanation:
Ok, so we have a long sandwich of 45 inches that will be divided in 3, giving us the following formula (x = shortest, y = medium, z=longest):
x + y + z = 45
Then we have middle piece (y) is 3 inches longer than the smallest (x):
y = x + 3
And the shortest piece (x) is 9 inches shorter than the longest (z):
x = z - 9 or z = x + 9
Let's place the found values of y and z in the first equation:
x + y + z = 45
x + (x + 3) + (x + 9) = 45
3x + 12 = 45
3x = 33
x = 11
So, x = 11, y = 14 and z = 20. (11 + 14 + 20 = 45).