If we remove a common factor from each of the terms in an expression we are reversing the distributive law:
When we factor we are applying the distributive law in reverse--reversing what we did when multiplying (which we did in the previous section). Note that we can always check our factoring by multiplying out our factored expression to see that we get what we started with.
Even though all the terms may not have a common factor, we can sometimes factor by first grouping the terms and then removing a common factor.
Be sure you've gone through each step in the examples above before doing these. Once you've worked them until you're sure that you understand them, go on to the next section. There are more problems of this type in the section test at the end of the section.
Note that you can get new practice problems by clicking the "Refresh" button at the bottom of the practice set.