mr. amato's class presentation
- 1. THE FOIL METHOD ALGEBRA I DECEMBER 18, 2008 A NEW AND EXCITING WAY TO MULTIPLY BINOMIALS INSTRUCTOR – TONY AMATO CA. CONTENT STANDARD 10
- 2. Students add, subtract, multiply, and divide monomials and polynomials. Students solve multi-step problems, including word problems, by using these techniques CALIFORNIA CONTENT STANDARD – 10
- 3. Objective The student will be able to: multiply two polynomials using the FOIL method.
- 4. 1) Multiply. (2x + 3)(5x + 8) Using the distributive property, multiply 2x (5x + 8) + 3 (5x + 8). 10x 2 + 16x + 15x + 24 Combine like terms. 10x 2 + 31x + 24 A shortcut of the distributive property is called the FOIL method.
- 5. The FOIL method is only used when you multiply 2 binomials. It tells you which terms to multiply. 2) Use the FOIL method to multiply the following binomials: (x + 3)(x + 7).
- 6. (x + 3)(x + 7). F tells you to multiply the FIRST terms of each binomial. x 2
- 7. (x + 3)(x + 7). O tells you to multiply the OUTER terms of each binomial. x 2 + 7x
- 8. (x + 3)(x + 7). I tells you to multiply the INNER terms of each binomial. x 2 + 7x + 3x
- 9. (x + 3)(x + 7). L tells you to multiply the LAST terms of each binomial. x 2 + 7x + 3x + 21 Combine like terms. x 2 + 10x + 21
- 10. Remember, FOIL reminds you to multiply the: F irst terms O uter terms I nner terms L ast terms
- 11. 3) Multiply. (x + 5)(x + 4) First terms: x 2 Outer terms: + 4x Inner terms: +5x Last terms: +20 Combine like terms. x 2 + 9x + 20
- 12. 3) Multiply. (3x - 5)(5x + 2) First terms: 15x 2 Outer terms: + 6x Inner terms: -25x Last terms: -10 Combine like terms. 15x 2 - 19x - 10
- 13. 4) Multiply (7p - 2)(3p - 4) First terms: 21p 2 Outer terms: - 28p Inner terms: - 6p Last terms: + 8 Combine like terms. 21p 2 - 34p + 8
- 14. 4) Multiply (5x - 2)(5x + 2) First terms: 25x 2 Outer terms: 10x Inner terms: - 10x Last terms: - 4 Combine like terms. 25x 2 + 0x – 4, now simplify 25x 2 – 4
- 15. ASSESSMENT TIME NOW THAT WE DID FOUR EXERCISES, DID ANYBODY GET THEM ALL CORRECT? HOW MANY WOULD LIKE TO REVIEW THE ENTIRE CONCEPT OF FOIL? WHO NEEDS FURTHER REVIEW OF MULTIPLYING VARIABLES AND COEFFICIENTS? WHO WOULD LIKE TO SEE MORE EXAMPLES OF FOIL?