This week we concluded our Radicals unit and began factoring polynomial expressions throughout the week we reviewed what we learned in grade 10 about radicals. The hardest part about this week was attempting to remember how to factor because haven’t done this in a full year.
For Example: x2 + 7x + 12
If you go through the factors of 12 you must find two number that adds to the second value in the expression(7)
1 * 12
2 * 6
3 * 4
4 * 3
Using the factors highlighted in red input them into your expression because 3 + 4 equals to 12
(x + 3) (x +4)
We were also taught what to do if the x2 value is greater than one. Ex: 2×2 + x – 6
To solve this we were introduced to the box method.
- Multiply 6 and 2x and find its factor. (12x) 3 and 4
- Fill in the first value in the top right corner
- Fill in the constant in the bottom right
- Fill in the two factors in the remaining corners
- Lastly find the common factor between the values from up to down and left to right
Claculations:
- 2×2 and 4x – 2x
- -3x and -6 – -3
- 2×2 and -3x – x
- 4x and -6 – 2
Final Answer: (2x – 3) (x + 2)