Spartan_Of_Ares
can i get help with rational expression
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Spartan_Of_Ares
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here it is
mathstudent55
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You mean a rational expression.
mathstudent55
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A simplified rational fraction can't have radicals in the denominator.
mathstudent55
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|dw:1356657899257:dw|
Spartan_Of_Ares
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cross multiplication?
mathstudent55
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Now you need to look at all prime factors of 98 and twelve.
mathstudent55
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No, we're just simplifying, one step at a time.
mathstudent55
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What are the prime factors of 98 and of 12?
Spartan_Of_Ares
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7 7 2 and 3 2 2
mathstudent55
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Great. Every two of the same factor can be taken out of the root.
Spartan_Of_Ares
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so 7 2 and 3 2
mathstudent55
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|dw:1356658078286:dw|
mathstudent55
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|dw:1356658116825:dw|
mathstudent55
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As you mentioned, the 7 came out in the numerator, and the 2 came out in the denominator. But we still have a radical in the denominator which we can't leave there.
Spartan_Of_Ares
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what would i do to remove it?
mathstudent55
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|dw:1356658236596:dw|
mathstudent55
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We are going to use both of the above ideas to remove the radical from the denominator.
First look at the denominator. What do you need to multiply the radical of the denominator to get rid of the radical? See example 1 above in drawing.
Spartan_Of_Ares
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@mathstudent55 times it self?
mathstudent55
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Right. If you multiply sqrt(3) by sqrt(3), you get sqrt(9) = 3, so you don't have a radical any more.
Spartan_Of_Ares
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so my denominator would be 18?
mathstudent55
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Now you need to look at example 2. in the drawing. If you multiply the denominator of the fraction by sqrt(3) what must you do to the numerator?
Spartan_Of_Ares
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multiply by the same
mathstudent55
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Exactly. So now look at the next drawing:
mathstudent55
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|dw:1356658755142:dw|
mathstudent55
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sqrt(9) is simply a whole number. That was the whole purpose of multiplying the denominator by sqrt(3)
Spartan_Of_Ares
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wait what do you mean do i just get\[18\] as my denominator?
mathstudent55
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You have 2 * sqrt(9) in the denominator. What is sqrt(9)?
mathstudent55
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Right. So now you have this:
|dw:1356658960784:dw|
mathstudent55
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One more step.
Spartan_Of_Ares
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6 is the denominator
mathstudent55
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Correct!
mathstudent55
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|dw:1356659058827:dw|
mathstudent55
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This is considered simplified.
Spartan_Of_Ares
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thank you for the help
mathstudent55
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You're welcome.