Question

Докажите равенство(корень15+4)/(4-корень15)=31+8 корень15

Answer 1

$frac{sqrt{15}+4}{4-sqrt{15}}=frac{(sqrt{15}+4)(4+sqrt{15})}{(4-sqrt{15})(4+sqrt{15})}=frac{4sqrt{15}+15+16+4sqrt{15}}{16-15}=31+8sqrt{15}$