When you see identical terms in two binomials and the signs are one plus and one minus (or one minus and then one plus), you have "the difference of squares." All you have to do is square the first and second terms and put a minus sign between them. (x^3+y^2)(x^3-y^2)=
The first thing I look for in simplifying (or solving) a rational expression or equation is an opportunity to factor common terms. In the numerator it's x^2, yielding x^2(x^6 +1). One of the x's of the x^2 in the numerator will cancel with the x in the
Or, if you wish, think of the variable as standing for a thing, such as "apples."
3apples - 3 apples = 0apples, or just plain 0 (zero).
Traditionally, people will tell you to use the "FOIL" method (First, Outside, Inside, Last). It works in this situation, but it doesn't if you don't have two binomials.
I like to think of it as a dance: each term on the left dances with each term on the right. Then you combine the "like...
Here's another way to look at it:
If you have a series of positive and negative numbers, group all the positives in one column and all the negatives in the other. Add the totals in each column (regardless of sign). Take the difference (subtract) between the two totals and apply...
Also, with the absence of a C, it means that you have k in common along with the factor of 9 in both terms. When you are looking to factor to help you solve or simplify, one "checkpoint" for you is to factor out common terms, such as numbers and/or variables.