Question

у - 1/у = 8 8/9 помогите плиз!

Answer 1

$y - frac{1}{y} =8 frac{8}{9} \ \ y- frac{1}{y} = frac{80}{9} \ \ y*y*9- frac{1*y*9}{y} = frac{80*9*y}{9} \ \ 9 y^{2} -9=80y \ 9 y^{2}-80y -9=0 \ D=-80 ^{2} -4*9*(-9)=6400+324=6724=82 ^{2} \ y_{1} = frac{80+82}{2*9} = frac{162}{18} =9 \ \ y_{2}= frac{80-82}{2*9} =- frac{1}{9}$
Ответ: у₁ = 9; у₂ = - 1/9.