Question

Докажите равенство:

Answer 1

$\frac{6- \sqrt{35} }{6+ \sqrt{35}} = \frac{(6- \sqrt{35})(6- \sqrt{35}) }{(6+ \sqrt{35})(6- \sqrt{35})} = \\ \frac{(6- \sqrt{35})^2}{36-35} = 36-2*6* \sqrt{35} +35=71-12 \sqrt{35}$