ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
Factoring Polynomials Videos 14 videos
CAHSEE Math: Algebra I Drill 6, Problem 2. Simplify the polynomial.
There are a variety of methods for factoring trinomials, Complete the square! Use the quadratic formula! Or be a genius and do it in your brain!
Factoring polynomials allows us to group things—and everything's always better in groups. Well... almost everything.
ACT Math 6.1 Elementary Algebra 214 Views
Share It!
Description:
ACT Math: Elementary Algebra Drill 6, Problem 1. Which of the following is not a factor of x 3 – x?
Transcript
- 00:02
And here's another shmoop du jour... Which of the following is not a factor of
- 00:06
x cubed minus x?
- 00:08
And here are the potential answers...
- 00:14
Okay can we factor?
- 00:15
Here, the common element on both sides of the minus sign is x.
Full Transcript
- 00:19
If we pull out that x...
- 00:20
...we get x times the quantity x squared minus 1.
- 00:24
But now we have x squared minus 1... it's a magic number we should recognize.
- 00:29
X squared minus 1 is a factorable beast...
- 00:33
...in quantity x plus 1 times quantity x minus 1.
- 00:38
So the factors are x... then quantity x plus 1... then quantity x minus 1.
- 00:43
If we look down our answers list, the only factor left that ISN'T an element of this
- 00:47
equation is x squared plus 1...
- 00:49
... so the answer is... E.
Related Videos
ACT Math: Plane Geometry Drill 3, Problem 1. What is the area of the trapezoid shape in the video?
ACT Math: Coordinate Geometry Drill 1, Problem 1. Which inequality is expressed by the number line?
ACT Math: Intermediate Algebra: Drill 3, Problem 1. Find the fifth number in the series.
CAHSEE Math: Algebra I Drill 6, Problem 2. Simplify the polynomial.