Final answer:
To find the length of the shorter piece of a board cut into two pieces where one is twice as long as the other, set up the equation x + 2x = 84. Solve for x to get x = 28 inches, which is the length of the shorter piece.
Step-by-step explanation:
The student is asking about dividing a board into two pieces, where one piece is twice as long as the other. To find the length of the shorter piece, we need to set up an equation based on the given relationship. Let's denote the length of the shorter piece as x inches. Therefore, the longer piece will be 2x inches. Together, these pieces should add up to the total length of the board which is 84 inches:
x + 2x = 84
Solving this equation:
3x = 84
Divide both sides by 3 to find the value of x:
x = 84 / 3
x = 28
So, the length of the shorter piece is 28 inches.