At a Glance - Word Problems
You might be getting ready to dive into the wonderful world of numbers, but that doesn’t mean you’ll be able to escape from English. Sorry, mathletes. Since algebra is simply a way of abbreviating real-life scenarios, it only makes sense that it'll be inextricably linked with written language.
That's right. Word problems are so fancy that we're busting out the extra syllables.
Let's take a look at an example.
Your mom gives you $50 to go to the store and buy milk (she didn’t have anything smaller, unfortunately...for her). Suppose you walk out with milk that costs $3.15, a box of cookies that costs $4.50, and a ton of magazines. When you get home, you hand your mom $2.35 in change. We have two questions for you:
- How are you going to get out of this one, especially after last week’s inflatable-pool-in-the-house fiasco?
- How much did you spend on all those magazines, anyway?
To solve this, all you have to do is turn the story into an equation. You started with $50, then spent $3.15, $4.50, and an unknown amount. After that, you gave $2.35 back to your mother. We can rewrite the situation this way, using the variable x for the unknown amount:
$50 – $3.15 – $4.50 – x – $2.35 = 0
If we combine the amount of money you spent and set that equal to the $50 you were originally given, we get this:
$50 = $10 + x
From here, you could subtract 10 from both sides, but it’s pretty easy to see from a glance that you must have spent a whopping $40 on those magazines—and we’re pretty sure you didn't buy any back issues of Good Housekeeping. On the upside, you’ll have plenty of time to peruse them all while you’re grounded for the next three days.