How to Use the FOIL Method of Mathematics

The FOIL method of mathematics is used to multiply two binomials (e.g., [x+5][x-2]) together by using the distributive property. It is an acronym that stands for First, Outer, Inner and Last, which outlines the procedure for multiplying two separate sets of binomials inside two separate sets of parentheses together.

Things You'll Need

• Paper
• A pencil
• An eraser

Instructions

1. To multiply the binomials (2x-5) and (x+4) together, first multiply the first term of each binomial in the parentheses: (2x)(x)=2x².

2. Multiply the two outer terms of each parentheses: (2x)(4)=8x.

3. Multiply the two inner terms of each parentheses: (-5)(x)=-5x

4. Multiply the last term in each set of parentheses: (-5)(4)=-20.

5. Write the answers on one line (2x²+8x-5x-20) and combine like terms. There are two like terms that are generally combined for FOIL problems: the terms that contain the x's of one degree, or the inner two terms. In this case, these terms are 8x and -5x. Combine them by adding 8x to -5x, which yields 3x.

6. Write the final answer on the next line: 2x²+3x-20.