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Factoring Polynomials Videos 14 videos
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.
Factoring polynomials by grouping is easy. You just combine like terms and then factor them out. Ta da!
ACT Math 4.5 Elementary Algebra 492 Views
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Description:
ACT Math: Elementary Algebra Drill 4, Problem 5. What is the solution to the problem shown?
Transcript
- 00:02
And here is your shmoop math question de jour
- 00:07
Multiply the quantity x minus 1 times the quantity x plus 1 times the quantity x minus 1
- 00:13
And here are the potential answers...
- 00:19
OK so what is this question asking?
- 00:22
This one is really about how neat we are.
Full Transcript
- 00:24
No, not how super-terrific and all-over groovy we happen to be,
- 00:28
but how tidy we are in terms of organizing our brute force methods of multiplying distributions.
- 00:35
Start with just the quantity x minus 1 times the quantity x minus 1.
- 00:39
Follow the arrows and we get x times x which is x squared
- 00:44
x times 1 which is x
- 00:46
... then negative 1 times x, which is negative x.
- 00:50
then negative 1 times 1, which is 1.
- 00:54
Now we just take the quantity x minus 1 and multiply it by the simplified x squared minus 1.
- 01:00
We get x times x squared, which is x cubed and note that since we have a cubed here,
- 01:06
we can eliminate 2 of the potential answers.
- 01:09
Now we've got x squared times negative 1, which is negative x squared,
- 01:12
then negative 1 times x which is negative x,
- 01:16
and finally negative 1 times negative 1 which is positive 1.
- 01:19
So the answer is right here: C.
- 01:22
Neat-o.
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