1. **State the problem:** We are given a graph representing the number of pages left to read ($L$) over time ($T$) with domain $0 \leq T \leq 6$ and range $0 \leq L \leq 150$. We want to find the equation that models the pages left to read as a function of time. 2. **Identify the type of function:** Since the pages left decrease as time increases, this suggests a linear relationship of the form $$L = mT + b$$ where $m$ is the slope and $b$ is the initial number of pages. 3. **Find the slope $m$:** The pages decrease from 150 at $T=0$ to 0 at $T=6$. The slope is $$m = \frac{0 - 150}{6 - 0} = \frac{-150}{6} = -25$$ 4. **Find the intercept $b$:** At $T=0$, $L=150$, so $$b = 150$$ 5. **Write the equation:** $$L = -25T + 150$$ 6. **Check the equation:** At $T=3$, $$L = -25(3) + 150 = -75 + 150 = 75$$ which fits the graph's midpoint. **Final answer:** $$L = -25T + 150$$