FOIL Method For Multiplying Two Binomials
FOIL Method is a technique that enables us to multiply two binomials in a very simple and easy way. But before explaining this method, it is necessary to recall the definition of binomial. A binomial is a special case of a polynomial, which is an algebraic expression consisting of only two terms separated by one of the + or - signs.
FOIL method mathematically
Foil method is a technique that makes it easier for a beginner student to remember the steps of the expanding process for an algebraic expression consisting of the product of two binomial terms written as follows:
The F-O-I- L acronym stands for First, Outer, Inner, and Last.
Let’s explain each of these terms:
- F: the first, that is, we multiply the first two terms from each parenthesis:
- O: the outers, ths is, we multiply the outermost terms of the two binomials:
- I: the inners, that is, we multiply the innermost terms of the two binomials:
- L: the last, that is, we multiply the last two terms from each parenthesis:
When we get the four sums, we simplify like terms by Combining Like Terms.
Note:
Let , , and a real numbers.
Warning!
Pay attention to the sign of the numbers , , and in the above formula.
Examples of How to Multiply Binomials using the FOIL Method
Example1:
Distribute and simplify the expression below using FOIL method:
Solution:
- First: multiply the first two terms from each binomial:
- Outer: we multiply the outermost terms of the two binomials:
- Inner: we multiply the innermost terms of the two binomials:
- Last: multiply the last two terms from each binomial:
Having applied the FOIL method, now we simplify the expression obtained using Combining Like Terms.
We have: and are like terms, hence:
Example2:
Distribute and simplify the expression below using FOIL method:
Solution:
- First: multiply the first two terms from each binomial:
- Outer: we multiply the outermost terms of the two binomials:
- Inner: we multiply the innermost terms of the two binomials:
- Last: multiply the last two terms from each binomial:
Having applied the FOIL method, now we simplify the expression obtained using Combining Like Terms.
We have: and are like terms, hence:
Example3:
Distribute and simplify the expression below using FOIL method:
Solution:
- First: multiply the first two terms from each binomial:
- Outer: we multiply the outermost terms of the two binomials:
- Inner: we multiply the innermost terms of the two binomials:
- Last: multiply the last two terms from each binomial:
Having applied the FOIL method, now we simplify the expression obtained using Combining Like Terms.
We have: and are like terms, hence:
Example4:
Distribute and simplify the expression below using FOIL method:
Solution:
- First: multiply the first two terms from each binomial:
- Outer: we multiply the outermost terms of the two binomials:
- Inner: we multiply the innermost terms of the two binomials:
- Last: multiply the last two terms from each binomial:
Having applied the FOIL method, now we simplify the expression obtained using Combining Like Terms.
We have: and are like terms, hence:
Example5:
Distribute and simplify the expression below using FOIL method:
Solution:
- First: multiply the first two terms from each binomial:
- Outer: we multiply the outermost terms of the two binomials:
- Inner: we multiply the innermost terms of the two binomials:
- Last: multiply the last two terms from each binomial:
Having applied the FOIL method, now we simplify the expression obtained using Combining Like Terms.
We have: and are like terms, hence:
Example6:
Distribute and simplify the expression below using FOIL method:
Solution:
- First: multiply the first two terms from each binomial:
- Outer: we multiply the outermost terms of the two binomials:
- Inner: we multiply the innermost terms of the two binomials:
- Last: multiply the last two terms from each binomial:
We don't have like terms in this expression, hence:
Example7:
Distribute and simplify the expression below using FOIL method:
Solution:
- First: multiply the first two terms from each binomial:
- Outer: we multiply the outermost terms of the two binomials:
- Inner: we multiply the innermost terms of the two binomials:
- Last: multiply the last two terms from each binomial:
Having applied the FOIL method, now we simplify the expression obtained using Combining Like Terms.
We have: and are like terms, hence:
Example1:
Distribute and simplify the expression below using FOIL method:
Solution:
- First: multiply the first two terms from each binomial:
- Outer: we multiply the outermost terms of the two binomials:
- Inner: we multiply the innermost terms of the two binomials:
- Last: multiply the last two terms from each binomial:
We don't have like terms in this expression, hence: