Solution:
Let "x" be the length of longer piece
Let "y" be the length of shorter piece
The length of a board is 55 inches
Therefore,
x + y = 55 -------- eqn 1
The board needs to be cut into 2 pieces with one piece 5 inches longer than the other piece
Therefore,
x = 5 + y ------- eqn 2
Substitute eqn 2 in eqn 1
5 + y + y = 55
2y = 55 - 5
2y = 50
Substitute y = 25 in eqn 1
x + 25 = 55
x = 55 - 25
Thus the length of longer piece is 30 inches