Free Algebra
Tutorials!
Home
Miscellaneous Equations
Operations with Fractions
Undefined Rational Expressions
Inequalities
Writing Equations for Lines Using Sequences
Intersections of Lines and Conics
Graphing Linear Equations
Solving Equations with Log Terms and Other Terms
Quadratic Expresions - Complete Squares
Adding and Subtracting Fractions with Like Denominators
Multiplying a Fraction by a Whole Number
Solving Equations with Log Terms and Other Terms
Solving Quadratic Equations by Factoring
Locating the Solutions of the Quadratic Equation
Properties of Exponents
Solving Equations with Log Terms on Each Side
http:
Graphs of Trigonometric Functions
Estimating Products and Quotients of Mixed Numbers
Inequalities
The circle
Adding Polynomials
Adding Fractions with Unlike Denominators
Factoring Polynomials
Linear Equations
Powers of Ten
Straight Lines
Dividing With Fractions
Multiplication Property of Equality
Rationalizing Denominators
Multiplying And Dividing Fractions
Distance Between Points on a Number Line
Solving Proportions Using Cross Multiplication
Using the Quadratic Formula
Scientific Notation
Imaginary Numbers
Values of Symbols for Which Fractions are Undefined
Graphing Equations in Three Variables
Writing Fractions as Decimals
Solving an Equation with Two Radical Terms
Solving Linear Systems of Equations by Elimination
Factoring Trinomials
Positive Rational Exponents
Adding and Subtracting Fractions
Negative Integer Exponents
Rise and Run
Brackets
Multiplying Square Roots
Multiplying Polynomials
Solving Systems of Linear Inequalities
Multiplication Property of Radicals
A Quadratic within a Quadratic
Graphing a Linear Equation
Calculations with Hundreds and Thousands
Multiplication Property of Square and Cube  Roots
Solving Equations with One Log Term
The Cartesian Coordinate Plane
Equivalent Fractions
Adding and Subtracting Square Roots
Solving Systems of Equations
Exponent Laws
Solving Quadratic Equations
Factoring Trinomials
Solving a System of Three Linear Equations by Elimination
Factoring Expressions
Adding and Subtracting Fractions
The parabola
Computations with Scientific Notation
Quadratic Equations
Finding the Greatest Common Factor
Introduction to Fractions
Simplifying Radical Expressions Containing One Term
Polynomial Equations
Graphing and Intercepts
The Number Line
Adding and Subtracting Rational Expressions with Different Denominators
Scientific Notation vs Standard Notation
Powers
Factoring by Grouping
Extraneous Roots
Variables and Expressions
Linera Equations
Integers and Substitutions
Squares and Square Roots
Adding and Subtracting Rational Expressions with Different Denominators
Solving Linear Inequalities
Expansion of a Product of Binomials
Powers and Exponents
Finding The Greatest Common Factor
Quadratic Functions
The Intercepts of a Parabola
Solving Equations Containing Rational Expressions
http:
Subtracting Polynomials
Solving Equations
Adding Fractions with Unlike Denominators
Solving Systems of Equations by Substitution
Solving Equations
Product and Quotient of Functions
Try the Free Math Solver or Scroll down to Tutorials!

 

 

 

 

 

 

 

 
 
 
 
 
 
 
 
 

 

 

 
 
 
 
 
 
 
 
 

Please use this form if you would like
to have this math solver on your website,
free of charge.


Solving Quadratic Equations by Factoring

Quadratic Equation

If a, b, and c are real numbers, with a 0, then the equation ax2 + bx + c = 0 is called a quadratic equation.

Keep the following strategy in mind when solving equations by factoring.

Strategy for Solving Equations by Factoring

1. Write the equation with 0 on the right-hand side.

2. Factor the left-hand side.

3. Use the zero factor property to get simpler equations. (Set each factor equal to 0.)

4. Solve the simpler equations.

5. Check the answers in the original equation.

 

Example

Solving a quadratic equation by factoring

Solve each equation.

a) 10x2 = 5x

b) 3x - 6x2 = -9

Solution

a) Use the steps in the strategy for solving equations by factoring:

10x2 = 5x   Original equation
10x2 - 5x = 0   Rewrite with zero on the right-hand side.
5x(2x - 1) = 0   Factor the left-hand side.
5x = 0 or 2x - 1 = 0   Zero factor property
x = 0 or   Solve for x.

The solution set is . Check each solution in the original equation.

b) First rewrite the equation with 0 on the right-hand side and the left-hand side in order of descending exponents:

3x - 6x2 = -9   Original equation
-6x2 + 3x + 9 = 0   Add 9 to each side.
2x2 - x - 3 = 0   Divide each side by -3.
(2x - 3)(x + 1)   Factor.
2x - 3 = 0 or x + 1 = 0    Zero factor property
or x = -1   Solve for x.

The solution set is . Check each solution in the original equation.

Caution

If we divide each side of 10x2 = 5x by 5x, we get 2x = 1, or . We do not get x = 0. By dividing by 5x we have lost one of the factors and one of the solutions.

 

All Right Reserved. Copyright 2005-2024