How do you rationalize $(3sqrt7) /( 5-sqrt7)$ ?

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Answer 1 · 2015-05-08T23:14:18

You can rationalize $(3sqrt(7))/(5-sqrt(7))$ by multiplying both the numerator and the denominator with the the denominator's conjugate

In this case, the denominator's conjugate is $sqrt(7)+5$ :
$(3sqrt(7) * (sqrt(7)+5) )/(5-sqrt(7) * (sqrt(7)+5) )$

This means the rationalized answer is $(15sqrt(7)+21)/(18)$

How do you rationalize (3sqrt7) /( 5-sqrt7)(3sqrt7) /( 5-sqrt7)?