Rasionalkan 10√21\2√3-√7

[tex] \frac{10 \sqrt{21} }{2 \sqrt{3}- \sqrt{7} } . \frac{2 \sqrt{3}+ \sqrt{7} }{2 \sqrt{3}+ \sqrt{7} } \\ \\ \frac{20 \sqrt{63}+10 \sqrt{147} }{5} \\\\ \frac{4.3 \sqrt{7}+2.7 \sqrt{3} }{1} \\\\ 12 \sqrt{7} + 14 \sqrt3} [/tex]