Rationalize the denominator: dfrac2sqrt7\\dfrac{2}{\\sqrt{7}}dfrac2sqrt7.
dfrac2sqrt8\\dfrac{2}{\\sqrt{8}}dfrac2sqrt8
2sqrt82\\sqrt{8}2sqrt8
dfrac2sqrt77\\dfrac{2\\sqrt{7}}{7}dfrac2sqrt77
dfrac27\\dfrac{2}{7}dfrac27