Question

Решите номер.Есть вложение.

Answer 1

$cfrac{13+ sqrt{69} }{13- sqrt{69}} + cfrac{13- sqrt{69} }{13+ sqrt{69}} = cfrac{(13+ sqrt{69})^2+(13- sqrt{69})^2 }{(13- sqrt{69})(13+ sqrt{69})}= \ = cfrac{169+ 26sqrt{69}+69+169-26 sqrt{69}+69 }{169-69}= cfrac{476 }{100}=4.76$