Foil Method of Multiplying Binomials

1. Multiply the First terms of each binomial. 2. Multiply the Inside terms and Outside terms of the product. Combine like terms. 3. Multiply the Last two terms of each binomial.

F L F L F O I L Multiply using FOIL: (x + 3 ) ( x + 2) = _ x 2_ +2x_ _+3x_ _+6_ = x2 + 5x + 6 O I I O

Notice that the two inside terms are like terms that can be added together. This method is known as the FOIL method. It gets its name from the process:

Try these. 4x+ 5x

1. (x + 4) ( x + 5 ) = _ x 2_ __+9x_ __+20 = x2 + 9x + 20

2. (x + 1) ( x + 3 ) = ______

3. (x + 7) ( x + 3 ) = ______

4. (x + 5) ( x + 6 ) = ______

5. (x + 8) ( 2x + 9 ) = ______

35x+7x 6. (5x + 6) ( x + 7 ) = _ 5x 2_ _+41x _+42_ = 5x2 + 41x + 42

7. (x + 2) ( 3x + 5 ) = ______

8. (3x + 8) ( 5x + 6 ) = ______

9. (x - 5) ( x – 4 ) = ______

10. (x - 8) (x – 3 ) = ______

11. (x - 2) (x – 4 ) = ______

12. (2x - 1) (x – 3 ) = ______

13. ( x - 5) (3x – 4 ) = ______

14. (2x – 3) (4x – 5) = ______

15. (2x - 5) ( 3x – 4 ) = ______

16. (2x - 5) ( x – 4 ) = ______

DIFFERENT SIGNS: +5x – 4x

1. (x - 4) ( x + 5 ) = _ x 2_ __+1x__ __-20__ = x2 + x - 20 2. (x + 1) ( x - 3 ) = ______

3. (x - 7) ( x + 3 ) = ______

4. (x + 5) ( x - 6 ) = ______

5. (x - 8) ( 2x + 9 ) = ______

6. (5x + 6) ( x - 7 ) = ______

7. (x - 2) ( 3x + 5 ) = ______

8. (3x + 8) ( 5x - 6 ) = ______

9. (x + 5) ( x – 4 ) = ______

10. (x - 8) ( x + 3 ) = ______

11. (x + 2) ( x – 4 ) = ______

12. (2x - 1) ( x + 3 ) = ______

13. ( x + 5) (3x – 4 ) = ______

14. (2 x – 3) (4 x + 5) = ______

15. (2x - 5) ( 3x + 4 ) = ______

16. (2x + 5) ( x – 4 ) = ______

17. ( x+ 3) ( x – 3) = ______

18. ( x+ 4) ( x – 4) = ______

19. ( x - 2 ) ( x + 2) = ______

20. ( x+ 7) ( x – 7) = ______

21. ( x – 9 ) ( x + 9 ) = ______

Evaluate for the given value(s) of the variable:

1. x2 + 4x - 5 for x = 2 2. 3x2 - 3x for x = -2 3. -2x2 - 4x + 5 for x = -3

4. x2 - 3xy + y2 for x = -1, y = 2 5. 2xy - x2 - 2y for x = -2, y = 3

H.W. Finish worksheet and Pg 218: odds 47-53; Pg 250: 1, 2, 3 (ans.to 2: 85) (034) Multiply using FOIL: Pg. 243: all 5-10, 13, 23, 24, all 37-41, 51, 52