Answer
When an equation models a real-world situation, the variables in the equation represent actual values of things from the real-world.
For example, let's consider the following equation:
$C = 2x+3y$
$C$ represents the total cost
$x$ represents the number of hats we buy at $\$2$ each
$y$ represents the number of books we buy at $\$3$ each
Work Step by Step
When an equation models a real-world situation, the variables in the equation represent actual values of things from the real-world. We can use the equation to make calculations about things that exist in the real world.
For example, let's consider the following equation:
$C = 2x+3y$
$C$ represents the total cost
$x$ represents the number of hats we buy at $\$2$ each
$y$ represents the number of books we buy at $\$3$ each
We can use this equation to calculate the total cost when we buy a certain number of hats and a certain number of books.