1. The problem asks to identify the independent and dependent variables in the statement: "As the elapsed time $t$ since a racecar leaves the starting line increases, the distance $d$ from the starting line increases." 2. The independent variable is the one that you control or that changes on its own, and the dependent variable depends on the independent variable. 3. Here, the elapsed time $t$ is the independent variable because it increases as time passes. 4. The distance $d$ depends on the elapsed time $t$, so $d$ is the dependent variable. Final answer: The independent variable is the elapsed time $t$, and the dependent variable is the distance $d$.