# Math 11 Pre-Calc, Week 5

This week in math we reviewed Factoring, this is something that we learned mostly in grade 10 math and you need it for the next unit in math 11 pre-calc. So this week we learned a saying that would help us. Its C.D.P.E.U. the C stands for Common so for example if you have $6x+8$  you can factor that as $2(3x+4)$ or $15x^2-20x^3$ to $5x^2(3y-4x)$. the next letter stands of Difference of Squares, so for example $x^2 - 9$ would be $(x+3)(x-3)$ or $16x^2 - 81$ would be $(4x+9)(4x-9)$ these are just numbers that are easy to factor and there easy because they are perfect squares so you already know what the number is going to be if you need to factor it. The next letter is P, it stands for pattern, so things like $x^2, x$ and any number so for example $x^2 + 5x + 6$ would be $(x+2)(x+3)$. The next letter means easy, so for example $2x^2 + 11x + 12$ would be easy since the numbers are small and only a few numbers can add up to 11 and a few can multiply to 12. The last letter means Ugly, this means ugly numbers like big numbers in you factoring so anything really above 12 or higher would be hard to factor since its a big number and it would take longer then normal to factor it.