SOLUTION: I need help really bad with a math problem, I tryed working on this all night last night and couldn't figure it out. Please help!!! Rationalize each denominator Adn please sho

Algebra ->  Radicals -> SOLUTION: I need help really bad with a math problem, I tryed working on this all night last night and couldn't figure it out. Please help!!! Rationalize each denominator Adn please sho      Log On


   

Question 169758: I need help really bad with a math problem, I tryed working on this all night last night and couldn't figure it out. Please help!!!
Rationalize each denominator Adn please show me how u work it out..Thank You
sqrt7 + 3/ sqrt7 - 3
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Rationalize each denominator Adn please show me how u work it out..Thank You
sqrt7 + 3/ sqrt7 - 3
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%28sqrt%287%29+%2B+3%29%2F%28sqrt%287%29+-+3%29 I think this is what you meant.
The object is to get rid of the radical in the DEN.
To do that, multiply NUM and DEN by the "conjugate." That term applies to complex numbers, I'm not sure it's the one for this problem, but the approach is similar.
The "conjugate" of (sqrt(7) - 3) is (sqrt(7) + 3), a change of sign.
%28sqrt%287%29+%2B+3%29%2F%28sqrt%287%29+-+3%29
=
= %28sqrt%287%29+%2B+3%29%2A%28sqrt%287%29+%2B+3%29%2F%287+-+9%29
= %287+%2B+6sqrt%287%29+%2B+9%29%2F%28-2%29
= -8+-+3sqrt%287%29
PS I looked it up, conjugate is the correct term.