Learning Resources

Investigation 5: Developing and Analyzing the Quadratic Formula

Assigned activities - Investigation 5 notes

Step A

If the house numbers differ by 2, then if x represents the first house number, then (x + 2) will represent the next house number . Now set up your quadratic equation to model the given problem, viz. product = 85 263

Step B

Simplify your equation and write it in standard form. Use the values for a, b and c from this form of the equation to solve the quadratic equation by substituting these values into the quadratic formula.

Make sure to simplify your answer as much as possible. You should find that the roots of the equation are -293 and 291

Step C

You should use completing the square or factoring to verify your roots.

Step D

This is an important step since roots or solutions to equations must be interpreted in terms of the problem or they have no meaning. In this example the negative root has no meaning. The house number cannot be -293.