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Adding and Subtracting Rational Expressions 1930 Views


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Description:

Don’t you hate it when you have too many rational expressions—or too few? Thank goodness for addition and subtraction. We don’t know what we’d do without those two.

Language:
English Language

Transcript

00:03

Adding and Subtracting Rational Expressions a la Shmoop

00:07

Scientists finally discovered that the duck-billed platypus is actually the result of an alien [Platypus being sucked into a UFO]

00:12

DNA-splicing experiment.

00:14

Let's help them to unsplice the duck out of the platypus and see what the heck it originally [Scientists with the platypus on an operating table]

00:18

was.

00:19

Of course, we're going to have to simplify things...

00:22

We'll be representing the unsplicing with the following equation...

00:25

Five x over x plus three minus x minus three over x plus three.

00:33

Duck DNA is mathematically represented by x minus three over x plus three. [Duck and a platypus with a DNA helix spinning behind them]

00:39

Since they have a common denominator…

00:41

…we can just squish them together into five x minus x minus three in parentheses, all [Hands squish the equation together]

00:47

over x plus three.

00:50

Getting rid of the parentheses, this breaks down into five x minus x plus three all over [Parentheses looks upset]

00:56

x plus three.

00:57

So the answer is four x plus three over x plus three.

01:01

This happens to be the DNA code for that kid from the Sixth Sense. [Kid with a duck on his knee]

01:04

We always wondered what happened to him. [Duck lays an egg]

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