Solving Quadratic Equations

1
Solving Quadratic Equations

• by Factoring

2
Solving Quadratic Equations by Factoring

• Get ZERO on one side by itself.
• Factor. Consider Common Factors FIRST!
• Set each factor 0.
• Solve each part.

3
Example 3-1a
Answer The solution set is 0, 4.
4
Example 3-1a
Check Substitute 0 and 4 in for x in the
original equation.
5
Example 3-1a
6
Example 3-1b
Answer 0, 3
7
Example 3-2a
Answer The solution set is 3.
8
Example 3-2a
9
Example 3-2b
Answer 5
10
Example 3-3a
Read the Test Item
You are asked to find the positive solution of
the given quadratic equation. This implies that
the equation also has a solution that is not
positive. Since a quadratic equation can either
have one, two, or no solutions, we should expect
this equation to have two solutions.
11
Example 3-3a
Solve the Test Item
Both solutions, 3 and 7, are listed among the
answer choices. However, the question asks for
the positive solution, 7.
Answer D
12
Example 3-3b
Answer C
13
Example 3-4a
14
Example 3-4a
15
Example 3-4b