Do Now 2/27/19 Take out your HW from last night. Punchline worksheet 13.11 Copy HW in your planner. Text p. 407, #4-36 evens In your notebook, list your thought process (questions you ask yourself) when you are given an expression to factor. Then factor the 5 expressions to the right. 3x² + 6x x² + 4x + 4 16x² – 49 x² – 7x + 10 3x² – 5x – 2
Factoring Polynomials Completely (1) Factor out greatest common monomial factor. (2) Look for difference of two squares or perfect square trinomial. (3) Factor a trinomial of the form x² + bx + c into binomial factors. (4) Factor a trinomial of the form ax² + bx + c into binomial factors. (5) Factor a polynomial with four terms by grouping. 3x² + 6x = 3x(x + 2) x² + 4x + 4 = (x + 2)(x + 2) 16x² – 49 = (4x + 7)(4x – 7) x² – 7x + 10 = (x – 2)(x – 5) 3x² – 5x – 2 = (3x + 1)(x – 2) -4x² + x + x³ - 4
“HE DIDN’T SEE THE EWE TURN” Homework Punchline worksheet 13.11 “Why Did the Boy Sheep Plunge Off a Cliff While Chasing the Girl Sheep?” SET 1 a) (a + 4)(a + 5) b) (a – 4)(a + 6) c) (a + 8)(a – 8) d) (a – 1)(5a + 4) e) (5a + 2)(5a + 2) SET 3 a) (k + 3)(8k + 1) b) (2k + 3)(4k – 1) c) (k – 1)(4k – 11) d) (2k + 11)(2k – 11) e) (k – 2)(11k + 8) SET 2 a) (u – 3)(2u – 5) b) (7 + 4u)(7 – 4u) c) (u – 7)(2u + 5) d) (u – 2)(7u + 2) e) (7u – 4)(7u – 4) SET 4 a) (9x² + y)(9x² – y) b) (x – 5y)(3x – 8y) c) (9x + y)(9x + y) d) (3x – y)(3x + 8y) e) (x + 4y)(9x + 2y) “HE DIDN’T SEE THE EWE TURN”
Learning Goal Learning Target SWBAT factor polynomials completely SWBAT simplify, factor, and solve polynomial expressions and equations Learning Target SWBAT factor polynomials completely
Factoring Polynomials Review (7.4) Greatest Common Factor (7.5) Factor x² + bx + c (7.6) Factor ax² + bx + c (7.7) Factor special products 6x² – 12x 6x(x – 2) x² – 7x – 30 (x – 10)(x + 3) 3z² + z – 14 (3z + 7)(z – 2) Perfect square trinomial Difference of two squares 72z² – 98 z² – 12z + 36 (z – 6)² 2(6z – 7)(6z + 7)
Section 7.8 “Factor Polynomials Completely” Factor out a common binomial- 2x(x + 4) – 3(x + 4) Factor by grouping- x³ + 3x² + 5x + 15
2x(x + 4) – 3(x + 4) 4x²(x – 3) + 5(x – 3) 2x(x + 4) – 3(x + 4) Factor out a common binomial 2x(x + 4) – 3(x + 4) Factor out the common binomial 2x(x + 4) – 3(x + 4) = (x + 4) (2x – 3) 4x²(x – 3) + 5(x – 3) Factor out the common binomial 4x²(x – 3) + 5(x – 3) = (x – 3) (4x² + 5)
7y(y – 2) + 3(2 – y) 7y(y – 2) – 3(y – 2) 7y(y – 2) – 3(y – 2) Factor out a common binomial 7y(y – 2) + 3(2 – y) The binomials y – 2 and 2 – y are opposites. Factor out -1 from 3(2 – y) to obtain -3(y – 2). 7y(y – 2) – 3(y – 2) Factor out the common binomial 7y(y – 2) – 3(y – 2) = (y – 2) (7y – 3)
2y²(y – 4) – 6(4 – y) 2y²(y – 4) + 6(y – 4) 2y²(y – 4) + 6(y – 4) Factor out a common binomial…Try It Out 2y²(y – 4) – 6(4 – y) The binomials y – 4 and 4 – y are opposites. Factor out -1 from -6(4 – y) to obtain 6(y – 4). 2y²(y – 4) + 6(y – 4) Factor out the common binomial 2y²(y – 4) + 6(y – 4) = (y – 4) (2y² + 6) = 2(y² + 3) (y – 4)
x³ + 3x² + 5x + 15 (x³ + 3x²) + (5x + 15) x² (x + 3) + 5 (x + 3) Factor by grouping x³ + 3x² + 5x + 15 Group terms into binomials and look to factor out a common binomial. (x³ + 3x²) + (5x + 15) x² (x + 3) + 5 (x + 3) Factor out each group Factor out the common binomial x²(x + 3) + 5(x + 3) = (x + 3) (x² + 5)
x³ – 3x² + 2x – 6 x³ – 6 + 2x – 3x² (x³ – 3x²) + (2x – 6) x² (x – 3) Factor by grouping…Try It Out Reorder polynomial with degree of powers decreasing from left to right. x³ – 3x² + 2x – 6 x³ – 6 + 2x – 3x² Group terms into binomials and look to factor out a common binomial. (x³ – 3x²) + (2x – 6) x² (x – 3) + 2 (x – 3) Factor out each group Factor out the common binomial x²(x – 3) + 2(x – 3) = (x – 3) (x² + 2)
Problem Solving (16 – w) (w) (w + 4) A box has a volume of 768 cubic inches and all three sides are different lengths. The dimensions of the box are shown. Find the width, length, and height. Volume = length x width x height (16 – w) (w) (w + 4) Substitute the possible solutions to see which dimensions work out. w = 12 w = 8 8 4 8 12 12 16 w = -8 w = 8 w = 12 Volume = 12 x 16 x 4 Can’t have negative width
Factoring Polynomials Completely (1) Factor out greatest common monomial factor. (2) Look for difference of two squares or perfect square trinomial. (3) Factor a trinomial of the form x² + bx + c into binomial factors. (4) Factor a trinomial of the form ax² + bx + c into binomial factors. (5) Factor a polynomial with four terms by grouping. 4x² + 10x = 2x(2x + 5) x² + 4x + 4 = (x + 2)(x + 2) 16x² – 49 = (4x + 7)(4x – 7) x² – 7x + 10 = (x – 2)(x – 5) 3x² – 5x – 2 = (3x + 1)(x – 2) -4x² + x + x³ - 4 = (x² + 1)(x – 4)
Homework Text p. 407, #4-36 evens