Algebraic expressions are really important in environmental science. They help us understand and solve problems we face in the real world. Here are a few ways they are used:

1. Pollution Levels: Scientists use algebra to figure out how much pollution is in the air or water. For example, if a factory dumps $x$ kilograms of waste into water every day, and the water can mix it away in $y$ cubic meters, we can find out how concentrated the pollution is. We can write it like this: $C = \frac{x}{y}$.

2. Population Growth: We can also use algebra to see how certain animal or plant populations grow over time. There’s a formula that looks like this: $P(t) = P_0 e^{rt}$. In this formula, $P(t)$ is the population at a time $t$, $P_0$ is how many there were to start, $r$ is how fast the population grows, and $e$ is just a special number used in math.

3. Resource Management: Algebra helps us plan our resources better. If $b$ is how much money we have for a project and each item we need costs $c$, we can find out how many items we can buy. We can calculate it like this: $n = \frac{b}{c}$.

Using these algebraic expressions allows researchers and decision-makers to make smart choices to help protect our environment!