Answer: the shorter piece is 30 inches long.
the longer piece is 120 inches long.
Explanation:
Let x represent the length of the shorter piece.
Let y represent the length of the longer piece.
A 150-inch pipe is cut into two pieces. It means that
x + y = 150- - - - - - - -1
One piece is four times the length of the other. It means that
y = 4x
Substituting y = 4x into equation 1, it becomes
x + 4x = 150
5x = 150
x = 150/5
x = 30
y = 4x = 4 × 30
y = 120