2変数の線形方程式でモデル化できる現実世界の状況は、人が稼ぐ金額と労働時間数との関係です。たとえば、人が1時間あたり10ドルを稼いでいる場合、式y = 10xで作業する時間の関数として収益を表すことができます。ここで、yは1ドルの収益であり、xは彼らが働く時間数です。。

この例では、ラインのYインターセプトは、労働時間数に関係なく、その人が稼ぐ最低金額を表します。ラインのXインターセプトは、その人が正確に0ドルを稼ぐために働かなければならない時間数を表します。ラインの勾配は、労働時間数が1つ増加するにつれて、人の収益の変化率を表します。この場合、勾配は10です。つまり、1時間ごとに人が働くことを意味し、収益は10ドル増加します。
A real-world situation that can be modeled with a two-variable linear equation is the relationship between the amount of money a person earns and the number of hours they work. For example, if a person earns $10 per hour, we can represent their earnings as a function of the number of hours they work with the equation y = 10x, where y is the person's earnings in dollars and x is the number of hours they work.

In this example, the y-intercept of the line would represent the minimum amount of money the person earns, regardless of the number of hours they work. The x-intercept of the line would represent the number of hours the person would have to work to earn exactly $0. The slope of the line represents the rate of change of the person's earnings as the number of hours they work increases by one. In this case, the slope is 10, which means that for every hour the person works, their earnings increase by $10.