Question

Rationalize the denominator of the following expression and simplify:

Answer 1

To "rationalize the denominator" is another way to say, getting rid of that pesky radical at the bottom.

we'll simply start by multiplying top and bottom by the "conjugate" of the denominator, recall difference of squares, anyhow, let's do so

$\bf \cfrac{6+\sqrt{2}}{5-\sqrt{2}}\cdot \cfrac{5+\sqrt{2}}{5+\sqrt{2}}\implies \cfrac{(6+\sqrt{2})(5+\sqrt{2})}{(5-\sqrt{2})(5+\sqrt{2})}\implies \cfrac{(6+\sqrt{2})(5+\sqrt{2})}{5^2-(\sqrt{2})^2} \\\\\\ \cfrac{30+6\sqrt{2}+5\sqrt{2}+(\sqrt{2})^2}{25-2}\implies \cfrac{30+11\sqrt{2}+2}{23}\implies \cfrac{32+11\sqrt{2}}{23}$