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Math Basics: Solving Rational Equations 20 Views
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Description:
We know we have more of an...irrational reputation over here, but stick with us. Today we'll solve this rational equation using lowest common multiples.
Transcript
- 00:03
Solving Rational Equations, a la Shmoop.
- 00:06
The brother of a handsome, but rather dopey, gold-medal swimmer also has a reality show. [Brother waves and other brother appears from a swimming pool]
- 00:12
His name is Brian and he is a mathematician.
- 00:16
Brian is trying to figure out how many viewers he can expect for his show. [Brian talking to a man at a table]
- 00:21
The network execs have given him a formula to figure out how many viewers Brian can expect.
Full Transcript
- 00:26
Seven over two v, plus one over four, equals eleven over four v.
- 00:33
Solving for v will tell us the number of viewers.
- 00:36
How many viewers will be tuning in to Brian’s show?
- 00:41
Here are your options.
- 00:43
First, Brian has to find the lowest common multiple, or LCM, of the denominator. [Boy solving maths problems]
- 00:49
This is only slightly more difficult than counting his brother's brain cells. [Brian counting brothers brain cells]
- 00:53
The lowest common multiple is 4v.
- 00:58
Multiplying seven over two v by two gives us fourteen over four v.
- 01:04
Multiplying one over four by v gives us v over 4v.
- 01:10
Eleven over four-v is fine.
- 01:12
Since every term in the equation is over 4v, we can just multiply the entire equation by
- 01:18
4v to get rid of it. Now we're left with fourteen plus v equals eleven. [LCM equation solved]
- 01:25
Subtract 14 from both sides to isolate v...
- 01:28
v equals eleven minus fourteen, which is negative three.
- 01:32
So the answer is B. Sorry, Brian. [Brian stood beside a pool]
- 01:36
We think that means that three people smashed their DVRs to avoid seeing the show. [Hammer smashes TV screen]
- 01:41
They'd rather see your brainless, shirtless brother...who's really fast at the 400 IM