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SAT Math 1.5 Algebra and Functions. If f (x) = x2 - 16 and g(x) = x4 - 256, what is f of x divided by g of x?
Simplifying Rational Expressions 1396 Views
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Description:
Rational expressions are too complex... it's about time someone simplified them.
- Mathematics and Statistics Assessment / Rational and Exponential Expressions, Equations, and Functions
- Algebra / Rewrite rational expressions
- Algebra / Rewrite rational expressions
- Algebra / Write expressions in equivalent forms to solve problems
- Algebra / Write expressions in equivalent forms to solve problems
- Algebra / Write expressions in equivalent forms to solve problems
Transcript
- 00:04
Simplifying Rational Expressions, a la Shmoop.
- 00:07
Sam is beginning his college career, and has just joined the fraternity Alpha Delta Nerda.
- 00:14
School policy says that no physical hazing is allowed...
- 00:17
...so Alpha Delta Nerda does its own kind of hazing...
- 00:20
...and makes the guys solve math problems to figure out what
Full Transcript
- 00:23
their "special number" will be for the rest of the year.
- 00:28
Sam gets an anonymous letter under his door that says,
- 00:31
Simplify 36 minus 3p all over 4p minus 48.
- 00:37
To start, let's take a look at the numerator to see if we can factor out anything.
- 00:41
We see that 3 is the greatest common factor of 36 and 3p,
- 00:45
3 goes into 36 twelve times and 3 goes into 3 one time...
- 00:50
...so 36 minus 3p becomes 3 times 12 minus p.
- 00:55
We can see that in the denominator the greatest common factor is 4.
- 00:59
4 goes into 4 one time and goes into 48 twelve times...
- 01:03
...so we can factor out the 4 to get 4 times p minus 12.
- 01:07
12 minus p is the same as p minus 12... when multiplied by a negative.
- 01:13
So we can pull out a negative 1 from the top...
- 01:18
to get negative 3 times p minus 12, over 4 times p minus 12.
- 01:27
The top and bottom of the expression have common factors of p minus 12,
- 01:32
so we can just cancel these out.
- 01:33
And we're left with negative three-fourths!
- 01:37
That's it! Sam's special number is negative three-fourths!
- 01:40
He has so got this college thing in the bag.
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