Question

Explain why Six less than three times a number is 21. Find the number.

Answer 1

Answer: 9

Step-by-step explanation: The reason that students get intimidated

by word problems is they try to look at all the information at once.

The best way to approach a word problem

is to break it down sentence by sentence.

In this problem, let's look at the first part of the sentence.

We know that six less than three times a number is 21.

Let's call the number x.

So we know that six less than three times a number means 3x - 6.

A common mistake would be for students to put 6 -  3x.

However, the word "less than" switches the order around.

So we know that six less than three times a number is 21.

So we can write this as 3x - 6 = 21.

Now we have an equation and we can solve for x.

First add 6 to both sides to get 3x = 27.

Now divide both sides by 3 to get x = 9.

So our answer to this word problem is 9.