In a recent post, we took a look at a classic SAT algebraic word problem and explained how to solve it with an algebraic equation—the approach that all of your math teachers encouraged in class. But on the SAT, working a problem out algebraically isn't always the best strategy. Maybe the equation presents some concept that you’re not comfortable with. Or maybe your mind is just blanking. When you find yourself in this situation, it's time to try plugging in.
If you've spent even a little bit of time prepping for The Test, you're probably familiar with the “plug in” approach. Basically, you take the given answers and stick them into the problem to see which one works. But with a little method, you can use plugging in to shave some time off your test. The key is to always start with C. Let’s work through an example:
In our last post, we looked at some questions involving functions, specifically functions involving money. Today, we’re going to continue our discussion with a look at how functions can be manipulated.
First of all, remember that evaluating functions involves simply plugging information in. For example, if f(x) = x + 1, then f(2) = 2 + 1 = 3.
The rules of function math are pretty simple: Treat the function like you would any other variable. Let’s jump in with a question:
Continuing with our discussion of tricky word problems, today we’re going to talk about word problems involving motion. Again, the difficulty in these questions lies in digging through the depths of confusing language to find your mathematical equation. Luckily, motion problems will tend to boil down to one simple equation:
