Multiply two term polynomials
When multiplying polynomials with two terms, you use the FOIL method. The FOIL method only works for multiplying two term polynomials. FOIL stands for first, outer, inner, last. This lets you know the order of how to distribute and multiply the terms. Let’s see how it works.
After FOILing, multiply the terms, group like terms, and add like terms if there are any.
Here is another helpful identity to use when multiplying two term polynomials:
Multiplying these polynomials is pretty simple because if you memorize these identities then you just plug in the values and have an answer.
Multiplying multiple term polynomials
You cannot use the FOIL method to multiply these polynomials. Instead, you have to multiply each term in one polynomial by each term in the other. You can do this by multiplying each term of one polynomial by the other polynomial. This can be tricky because it is easy to miss one term. When we do examples of this, it will become easier to understand how to solve them.
When multiplying polynomials, you may come across multiplying variables with exponents by variables with exponents. In this case, we use this exponent rule:
For this rule, the base or variable must be the same. When multiplying variables with exponents, you add the exponents together.
Let’s see some examples to understand how to multiply polynomials.
First example (click here):
We will use the FOIL method to solve this.
1. Use FOIL identity
2. Multiply terms )
3. Group like terms
(Luckily, everything was already grouped together)
4. Add like terms
Next example (click here):
Here, we can use another one of the identities for multiplying two term polynomials.
1. Use
2. Simplify
Last example (click here):
1. Multiply each term in one polynomial by the other polynomial
2. Distribute and multiply
3. Group like terms
4. Add like terms
Multiplying polynomials looks intimidating, but as long as you keep your work neat and double check your work, it should be pretty easy. Practice will be one of the biggest things that will help you. The more you practice, the easier multiplying polynomials will be because you will get the hang and flow of how to multiply them. Check out Symbolab’s Practice for more help and practice.
Until next time,
Leah