Factoring Review 25 January 2011 Factoring n n

Factoring Review 25 January 2011

Factoring n n n The process of rewriting an equation or expression as the product of its factors Example: x 2 + 3 x + 2 = (x + 2)(x + 1) Most common form is the quadratic form: ax 2 + bx + c, a ≠ 0

Factoring (when a = 1) ax 2 + bx + c = (x + ___ ) multiply to equal c and add up to equal b You can always check your answer by FOIL-ing!

Finding Factors of C 1. 2. 3. 4. 5. Identify the value of c On your calculator, go to the y= screen Type C/X into y 1 Go to the table Any whole numbers (positive, nondecimal numbers) in the y 1 column are factors of c

Example

Example #1

Example #2

Example #3

Your Turn: n n Complete problems 1 – 4 on the “Factoring Practice” handout Check your answer by FOIL-ing!

Difference of Squares n When we use it: n n Usually in the form ax 2 – c Both a and c are perfect squares (the square root of each number is a whole number)

Example #1

Example #2

Your Turn: n n Complete problems 5 – 10 on the “Factoring Practice” handout Remember to check your answer by FOIL-ing!

Factoring (when a ≠ 1): The Welsh Method 1. 2. 3. 4. 5. Multiply c and a Rewrite the expression with the new value for c Write (ax + ) Finish “factoring” the new expression Reduce each set of parentheses by any common factors

Example #1

Example #2

Example #3

Your Turn: n n Complete problems 11 – 20 on the “Factoring Practice” handout Don’t forget to check by FOIL-ing!