1.  Adding and Subtracting Polynomials Section 9-2

2. Adding Polynomials We have 2 methods to add polynomials Method 1: You can add polynomials by grouping the like terms horizontally together and finding their sum. Method 2: You can add polynomials by grouping the like terms vertically together (stacking method) and finding their sum.

3. Find each sum. 1. (4 x - 3) + (2 x + 5) Method 1Method 2

4. 2. (x 2 + 2x – 5) + (3x 2 – x + 4)

5. 3. (2x 2 + 5xy + 3y 2 ) + (8x 2 – 7y 2 )

6. Your Turn! 1. (3x + 9) + (5x + 3) 2. (-2 x 2 + x + 5) + ( x 2 - 3 x + 2) 3. ( a 2 - 2 ab + 4 b 2 ) + (7 a 2 - 2 b 2 ) 4. (7 m 2 – 6) + (5 m - 2)

7. Subtracting Polynomials Recall that subtracting an integer is really adding its opposite. 4 - 3 = 4 + -32 – 3 = 2 + -3 To subtracting polynomials ADD THE OPPOSITE!

8. Find each difference 1. (6 x + 5) – (3 x + 1)

9. 2.) (2 y 2 – 3 y + 5) – ( y 2 + 2 y +8)

10. 3.) (3 x 2 + 5) – (-4 x + 2 x 2 + 3)

12. Your Turn! 1. (3 x – 2) – (5 x – 4) 2. (10 x 2 + 8 x - 6) – (3 x 2 + 2 x – 9) 3. (6 m 2 + 7) – (-2 m 2 + 2 m - 3) 4. (5 x 2 – 4 x ) – (2 – 3 x )

13. Geometry Link! The perimeter of triangle ABC is 7 x + 2 y. Find the measure of the third side of the triangle. 2x+ y 3x - 5y