Factoring Pattern x2 + bc + c, c negative Chapter 5 Section 5.8

Objective Students will factor quadratic trinomials whose quadratic coefficient is 1 and whose constant term is negative

Concept The factoring that you did in the last lesson had this pattern: x2 + bx + c = (x + r)(x + s) The factoring that you will do in this lesson has the following pattern: c negative r & s opposite signs

Concept When you find the product of (x + r)(x + s), you obtain x2 + bx + c = x2 + (r + s)x + rs

Concept Therefore, the method used in this lesson is the same as before. You find two numbers, r and s, whose product is c and whose sum is b. Since c is negative, one of r and s must be negative and the other must be positive.

Example x2 – x – 20

Example a2 + 29a - 30

Example x2 – 4kx – 12k2

Questions

Assignment Worksheet