FOIL Calculator


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A diagram showing two binomials multiplied together with the FOIL method

This calculator uses the first-outer-inner-last (FOIL) method to multiply two binomials. This page includes an explanation of the method as well as example computations with steps.

This diagram shows how the FOIL method is used to multiply the two binomials.

How to Use This Calculator

  1. Enter the coefficients for a, b, c, and d in the input fields.

Once all coefficients are entered, the result will be computed.

Understanding the Formula

(ax+b)(cx+d)\left(ax+b\right)\left(cx+d\right)

The FOIL method is used to multiply two binomials that are in this form.

The steps of FOIL are as follows:

  1. First (F) - Multiply the first terms

    ax×cx=acx2ax\times cx=acx^2
  2. Outer (O) - Multiply the outer terms

    ax×d=adxax\times d=adx
  3. Inner (I) - Multiply the inner terms

    b×cx=bcxb\times cx=bcx
  4. Last (L) - Multiply the last terms

    b×d=bdb\times d=bd
  5. Add the products

    acx2+adx+bcx+bdacx^2+adx+bcx+bd
  6. Combine like terms

    acx2+(ad+bc)x+bdacx^2+\left(ad+bc\right)x+bd

The final result is

acx2+(ad+bc)x+bdacx^2+\left(ad+bc\right)x+bd

Example Problem

(5x+4)(3x+2)\left(5x+4\right)\left(3x+2\right)

In this example, the values of the coefficients are as follows:

  • a = 5
  • b = 4
  • c = 3
  • d = 2

The steps to solve this expression:

  1. First (F) - Multiply the first terms

    ax×cx=acx2ax\times cx=acx^25x×3x=15x25x\times 3x=15x^2
  2. Outer (O) - Multiply the outer terms

    ax×d=adxax\times d=adx5x×2=10x5x\times 2=10x
  3. Inner (I) - Multiply the inner terms

    b×cx=bcxb\times cx=bcx4×3x=12x4\times 3x=12x
  4. Last (L) - Multiply the last terms

    b×d=bdb\times d=bd4×2=84\times 2=8
  5. Add the products

    acx2+adx+bcx+bdacx^2+adx+bcx+bd15x2+10x+12x+815x^2+10x+12x+8
  6. Combine like terms

    acx2+(ad+bc)x+bdacx^2+\left(ad+bc\right)x+bd15x2+(10+12)x+815x^2+\left(10+12\right)x+815x2+22x+815x^2+22x+8

The final result is

15x2+22x+815x^2+22x+8