1. Problem: Determine whether the function $f(x) = -5x + 10$ is one-to-one. 2. A function is one-to-one if each $y$ value corresponds to exactly one $x$ value. 3. Linear functions of the form $f(x) = mx + b$ with $m \neq 0$ are one-to-one because they have a constant slope and never repeat $y$ values. 4. Here, $f(x) = -5x + 10$ has slope $m = -5 \neq 0$, so it is one-to-one. 5. The graph of $f(x) = -5x + 10$ is a straight line with intercept at $(0,10)$ and slope $-5$. 6. The function passes the horizontal line test, confirming it is one-to-one. Final answer: $f(x) = -5x + 10$ is one-to-one.