How to Factor Equations

A quadratic equation's factors are expressions with two terms.
••• Digital Vision./Digital Vision/Getty Images

One way of solving quadratic equations is by factoring the equation and then solving each part of the equation for zero.

Factoring Quadratic Equations

    Solve the equation for zero.

    Example: (x^2)-7x=18 --->(x^2)-7x-18=0 by subtracting 18 from both sides.

    Factor the left side of the equation by determining two numbers that add up to, in this case, -7, and can be multiplied together to get -18.

    Example: -9 and 2 -9*2=-18 -9+2=-7

    Put the left side of the quadratic equation into two factors that can multiplied out to get the original quadratic equation.

    Example: (x-9)(x+2)=0

    Because x_x=x^2 -9x+2x=-7x -9_2=-18

    So you can see that all the elements of the original quadratic equation are there.

    Solve each factor of the equation for zero to get your solution set for the quadratic equation.

    Example: x-9=0 so x=9 x+2=0 so x=-2

    So, your solution set for the equation is {9, -2}

    Things You'll Need

    • Equation
    • Paper
    • Pencil

Related Articles

How to Factor Polynomials With 4 Terms
How to Factorise a Quadratic Expression
How to Factor Binomial Cubes
How to Factor Trinomials on a TI-84
How to Calculate Grams From Normality
How to Divide Rational Numbers
How to Find Intercepts in a Rational Function
How to Do Multiplying & Factoring Polynomials
How to Calculate Volume of a Rectangular Prism
How to Factor Polynomials with Coefficients
How to: Improper Fractions Into Proper Fractions
Tricks for Factoring Quadratic Equations
How to Use Elimination to Solve the Linear Equation
How to Solve a Parabola
Adding & Subtracting Fractions
How to Calculate a Sigma Value
How to Factor Higher Exponents
How to Find Equations of Tangent Lines
How to Solve Higher Degree Polynomials
How to Write Polynomial Functions When Given Zeros

Dont Go!

We Have More Great Sciencing Articles!