Question

Докажите равенство: $frac{6- sqrt{35} }{6+ sqrt{35} } = 71-12 sqrt{35}$

Answer 1

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