Robin helped her mom set a banquet table for dinner. She noticed that the width of the table was a third of its length. If the width is 6 feet, write and solve an equation to determine its length.


A$\frac{L}{3} = 6; L = 18$ feet
B$3L = 6; L = 2$ feet
C$3 + L = 6; L = 3$ feet
D$L - 3 = 6; L = 9$ feet

Verified Answer :

  • Represent the relationship between the width \(W\) and length \(L\) of the table as \(\frac{L}{3} = W\).
  • Substitute the given width \(W = 6\) into the equation to get \(\frac{L}{3} = 6\).
  • Multiply both sides by \(3\) to find the length: \(L = 18\) feet.
  • Select the matching option: \(\boxed{\frac{L}{3} = 6; L = 18 \text{ feet}}\).

Explanation

  1. Problem Analysis and Formulation

We are given that the width of the table is \(W = 6\) feet and that the width is a third of its length \(L\). We can translate this relationship into a mathematical equation:
\[W = \frac{1}{3}L\]
Or equivalently:
\[\frac{L}{3} = W\]
Our goal is to write this equation using the given width and then solve it for the unknown length \(L\).

  1. Solving the Equation

Since we know the width \(W = 6\) feet, we can substitute this value directly into the equation \(\frac{L}{3} = W\):
\[\frac{L}{3} = 6\]
To solve for \(L\), we multiply both sides of the equation by \(3\):
\[L = 6 \times 3\]
\[L = 18\]
Thus, the length of the table is \(18\) feet.

  1. Final Conclusion and Selection

Comparing our derived equation \(\frac{L}{3} = 6\) and our solution \(L = 18\) feet with the provided options, we can see that the first option matches our findings perfectly:

  • \(\frac{L}{3} = 6; L = 18\) feet
  • \(3L = 6; L = 2\) feet
  • \(3 + L = 6; L = 3\) feet
  • \(L - 3 = 6; L = 9\) feet

The correct choice is the first one.

Examples

Understanding how to translate word problems into algebraic equations is a foundational skill in many fields. For example, if you are planning to build a rectangular vegetable garden, you might decide that your garden should be twice as long as it is wide. If you know you have enough space for a width of 4 meters, you would set up the equation \(\frac{L}{2} = 4\) to find that you need 8 meters of length. This helps you plan your materials and space efficiently!