1. Do Now Pass out calculators. Write down the weeks assignments. Pick up a worksheet from the back and wait for instructions.

2. Objective: To divide polynomials.

3. SOLUTION Divide a polynomial by a monomial EXAMPLE 1 Divide 4x 3 + 8x 2 + 10x by 2x. Method 1 : Write the division as a fraction. Write as fraction. Divide each term by 2x. = 2x 2 + 4x + 5 8x28x2 4x34x3 2x2x 2x2x 10x 2x2x ++= Simplify. (4x 3 + 8x 2 + 10x) 2x 4x 3 + 8x 2 +10x 2x2x =

4. Divide a polynomial by a monomial EXAMPLE 1 CHECK 2x(2x 2 + 4x + 5) = 4x 3 + 8x 2 + 10x ? 2x(2x 2 ) + 2x(4x) + 2x(5) = 4x 3 + 8x 2 + 10x ? 4x 3 2x = ? Think 8x 2 2x = ? Think 10x 2x = ? Think + 4x + 5 ANSWER (4x 3 + 8x 2 + 10x) 2x = 2x 2 + 4x + 5 2x 4x 3 + 8x 2 + 10x ) 2x22x2 4x 3 + 8x 2 + 10x = 4x 3 + 8x 2 + 10x

5. GUIDED PRACTICE for Example 1 (6x 3 + 3x 2 –12x) 3x1. 2x 2 + x – 4 ANSWER (12y 4 – 16y 3 + 20y 2 ) 4y2. ANSWER 3y 3 – 4y 2 + 5y

6. SOLUTION EXAMPLE 2 Divide a polynomial by a binomial Divide x 2 + 2x – 3 by x – 1. STEP 1 Divide the first term of x 2 + 2x – 3 by the first term of x – 1. Multiply x and x – 1. x x – 1x 2 + 2x – 3 x 2 – x 3x3x Subtract x 2 – x from x 2 + 2x. Think : x 2 x = ?

7. EXAMPLE 2 Divide a polynomial by a binomial Bring down –3. Then divide the first term of 3x – 3 by the first term of x – 1. + 3 3x – 3 0 Multiply 3 and x – 1. Subtract 3x – 3 from 3x – 3. STEP 2 Think : 3x x = ? ANSWER (x 2 + 2x – 3) (x – 1) = x + 3 x – 1x 2 + 2x – 3 x 2 – x 3x – 3 x

8. EXAMPLE 3 Divide a polynomial by a binomial Divide 2x 2 + 11x – 9 by 2x – 3. x 2x 2 –3x 2x – 3 2x 2 + 11x – 9 14x – 9 12 Multiply x and 2x – 3. Subtract 2x 2 – 3x. Bring down – 9. Multiply 7 and 2x – 3. Subtract 14x – 21. ANSWER (2x 2 + 11x – 9) (2x – 3) = x + 7 + 12 2x – 3 14x – 21 + 7

9. GUIDED PRACTICE for Examples 2 and 3 3. Divide: (a 2 + 3a – 4) (a + 1) a + 2 + ANSWER – 6 a + 1 4. Divide: (9b 2 + 6b + 8) (3b – 4) ANSWER 3b + 6 + 32 3b – 4

10. EXAMPLE 4 Rewrite polynomials Divide 5y + y 2 + 4 by 2 + y. Rewrite polynomials. Multiply y and y + 2. y 2 + 2y Subtract y 2 + 2y. Bring down 4. 3y + 4 Multiply 3 and y + 2. 3y + 6 Subtract 3y + 6. – 2 y + 2 y 2 + 5y + 4 y ANSWER (5y + y 2 + 4) (2 + y) = y + 3 + y + 2 – 2 + 3

11. EXAMPLE 5 Insert missing terms Divide 13 + 4m 2 by – 1 + 2m. Rewrite polynomials, Insert missing term. 2m2m 2m – 1 4m 2 + 0m + 13 Multiply 2m and 2m – 1. 4m 2 – 2m Subtract 4m 2 – 2m. Bring down 13. 2m + 13 Multiply 1 and 2m – 1. 2m – 1 Subtract 2m – 1. 14 ANSWER (13 + 4m 2 ) (– 1 + 2m) = 2m + 1 + 2m – 1 14 + 1

12. GUIDED PRACTICE for Examples 4, 5, and 6 5. Divide: (8m – 7 + 4m 2 ) (5 + 2m) ANSWER 2m – 1+ 2m + 5 – 2 6. Divide: (n 2 – 6) (– 3 + n) n + 3 + ANSWER n – 3 3

13. Exit Ticket: 1. Divide 6x 3 – 12x 2 + 9x by 3x. 1. Divide x 2 + x – 6 by x + 3. 1. Divide 3x 2 + 17x + 13 by 3x + 2. 1. Divide -12 + 4y 2 by -1 + 2y.