How do you use factoring in quadratic equations?
To solve a quadratic equation by factoring, follow this five-step process:
- Put all terms on one side of the equal sign, leaving zero on the other side.
- Factor.
- Set each factor equal to zero.
- Solve each of these equations.
- Check by inserting your answer in the original equation.
Example: Solve x2 – 6x = 16.
Following the steps,
x2 - 6x becomes x2 - 6x - 16 = 0
Factor
(x - 8)(x + 2) = 0
x - 8 = 0 or x + 2 = 0
x = 8 x = -2
Then to check,
82 - 6(8) = 16 or (-2)2 - 6(-2) = 16
64 - 48 = 16 4 + 12 = 16
16 = 16 16 = 16
Both values, 8 and –2, are solutions to the original equation.