Question

Rationalize the denominator of

Answer 1

\[\frac{a}{b+\sqrt c}\]\[=\frac{a}{b+\sqrt c}\times1\]\[=\frac{a}{b+\sqrt c}\times\frac11\]\[=\frac{a}{b+\sqrt c}\times\frac{b-\sqrt c}{b-\sqrt c}\]\[=\frac{a(b-\sqrt c)}{(b+\sqrt c)(b-\sqrt c)}\]\[=\frac{a(b-\sqrt c)}{b^2-c}\]