Math Basics: Solving Rational Equations

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

00:26

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