In this lesson we will factor polynomials To factor polynomials, we must first learn to divide monomials
Simplify the expression Write the expression without exponents
Now cancel to simplify the expression 4
Next, we will factor polynomials What does each term in the polynomial have in common? 3x3 + 6x2 + 9x
Each term is divisible by 3 and x We can ‘factor out’ the greatest common factor. 3x3 + 6x2 + 9x 3x(x2 + 2x + 3)
Factor out the greatest common factor in this polynomial 15x2 – 12x3 Each term contains the factor 3x2 3x2(5 – 4x)
The polynomial is modeled x2 + 4x + 3 What are the factors?
Place x’s and 1’s on the top and left side to model the factors x2 + 4x + 3 x + 3 x +1
Write the polynomial as the product of two binomials x + 3 x2 + 4x + 3 x +1 (x + 3)(x + 1)
Factor the polynomial x2 + 6x + 9
Write as a product of binomials x2 + 6x + 9 (x + 3)(x + 3) or (x + 3)2
Factor out the greatest common factor -15x2 + 35x Since the expression begins with a negative, factor out –5x -5x(3x – 7)
We can also factor with a box 6x2 + 4x + 3x + 2 First, place the polynomial in a box 6x2 4x 3x 2
Next factor out the greatest common factor 6x2 + 4x + 3x + 2 3x + 2 2x +1 6x2 4x 3x 2
Write the polynomial as the product of two binomials 6x2 + 4x + 3x + 2 (3x + 2)(2x + 1) 3x + 2 2x +1 6x2 4x 3x 2
Complete Activity 9c Divide Monomials Factor out the Greatest Common Factor Factor Polynomials with Algebra tiles Factor Polynomials with a box