Factoring GCF and Trinomials
Greatest Common Factor The Greatest Common Factor is the largest number that will divide into a group of numbers Examples: 6, 9 15, 55 GCF = 3 GCF = 5
3. What is the greatest common factor?? 36 24 The number 12
GCF with Variables Note: With variables, the GCF will Always be the smallest exponent of a Common variable Examples: 12x3, 16x2 45a5, 50a7 GCF = 4x2 GCF = 5a5
6. What is the greatest common factor?? The GCF is 5a
What is the greatest common factor?? 7. 3y -8xy y 11x 8. 22x2 – 11x -x2 9. -4x6 - x4 - 2x2
Factoring means to write as a product Always look for a Greatest Common Factor 1st. Factor 4x + 6y What is their greatest common factor? = 2( ) 2x + 3y Lets check. =2(2x+3y) = 4x+6y
= y( ) 3 – 8x = 2a( ) a2 – 3b2 Factor 11. 3y – 8xy 12. 2a3 – 6ab2 What is their GCF? = y( ) 3 – 8x 12. 2a3 – 6ab2 = 2a( ) a2 – 3b2
= 2k( ) h2 + 1 = 3v( ) 2u + 3v Factor 13. 2h2k + 2k 14. 6uv + 9v2 What is their GCF? = 2k( ) h2 + 1 14. 6uv + 9v2 = 3v( ) 2u + 3v
What if there is not GCF? 3x + 2 Then it is prime x2 + 3x + 2 Unless it is a trinomial, then I have to use another method.
GCF Factor: xy – 5y What is common? Answer: y(x - 5) What if we change the expression slightly? x(x + 4) – 5(x + 4) Answer: (x + 4)(x – 5 )
GCF Try these: 3x2 – 6x – 15x3 16x2 – 8x y(y – 6) + 9(y – 6)