Lesson 2-4 Write Quadratic

Lesson 2-4 Write Quadratic

Equations from Factors(Roots)

Objective: Find a quadratic equation that has given roots

using reverse factoring

Here we will take our solutions and work backwards to find what quadratic goes with the solutions.

If we have rational solutions we can use factoring in reverse, we will set each solution equal to x
and then make the equation equal to zero by adding or subtracting.

Once we have done this our expressions will become the factors of the quadratic.

Example 1. The solutions are 4 and − 2

Set each solution equal to x

If one or both of the solutions are fractions we will clear the fractions by
multiplying by the denominators.