Rationalize the denominator. 
$-\(\frac{5}{2\sqrt7}\)$

Rationalize each denominator. Assume all variables represent nonnegative numbers and that no denominators are 0.

$\frac{a}{(\surd a+b)-1}$

Rationalize each denominator. Assume all variables represent nonnegative numbers and that no denominators are 0. 5√x / (2√x + √y)

Rationalize each denominator. Assume all variables represent nonnegative numbers and that no denominators are 0. (9 - r) / (3 - √r)

Rationalize each denominator. Assume all variables represent nonnegative numbers and that no denominators are 0. (1 + √3) / (3√5 + 2√3)

Rationalize the denominator. $\(\frac{6+\sqrt{x}\)}{-\(\sqrt{x}\)}$

Rationalize the denominator and simplify the radical expression.

$\(\frac{2-\sqrt3}{2+\sqrt3}\)$

Rationalize the denominator and simplify the radical expression.

$\(\frac{\sqrt7}{5-\sqrt6}\)$

Rationalize the denominator.

$\(\frac{1}{\sqrt7}\)$