Week 5- Factoring Polynomials

In week 5 of Pre-calc, we learned about factoring polynomials and the rules on how to do so. Factoring is writing an expression as a product of factors. Their are different steps that we need to take when factoring, CDPEU (Common, Difference of squares, Pattern, Easy, Ugly/Can Divers Pee Easily Underwater).

Example: Factor

x^2 - 2x-15

(x+3)(x-5)

This is an easy trinomial partern because it has no term at the front of x^2 and this includes the difference of squares because it is subtracting. How we got +3 and -5 is that -15= -5 \cdot 3 and if the second term in the pattern (-2x) is a negative than the larger term (which is 5) takes the negative sign (not 3) because -5+3=2.

Example: Factor an Ugly polynomial

If a polynomial is Ugly then it has a term in front of the first trinomial pattern ( #x^2 ).

8x^2 + 18x + 4  (divide the terms by 2 because they are common)

2 ( 4x^2 + 9x + 2)

2(4x+1)(x+2)

How we got the factored product; we have to multiply 4x^2 with 2 which got us 8x^2 and the common factors of 8x^2 were 8x \cdot 1x = 8x^2 and 8x+1x= 9x. How we got 2(4x+1)(x+2); *use the box method it will help youuu. The numbers outside of the magical box are the terms that are common within the terms inside the magical box.

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