x is the length of the first piece.
"the second piece is 3 times as long as the first piece"
The second piece measures 3x.
"the third piece is 4 times as long as the first piece"
The third piece measures 4x.
The three pieces measure x, 3x, and 4x.
Altogether, they measure 56 inches, so wee add the three lengths ans set equal to 56.
x + 3x + 4x = 56
8x = 56
x = 7
3x = 3(7) = 21
4x = 4(7) = 28
Answer: The pieces measure 7 inches, 21 inches, and 28 inches.
