Question

Номер 1034
Срочно надо!

Answer 1

$1);x+frac2x=7frac27\frac{x^2+2}x=frac{51}7\7x^2+14=51x\7x^2-51x+14=0\D=2601-4cdot7cdot14=2601-392=2209=(47)^2\x_{1,2}=frac{51pm47}{14}\x_1=frac27,;x_2=7\\2);y-frac y7=5frac17\frac{7y-y}7=frac{36}7\frac{6y}7=frac{36}7\y=6\\3);y-frac1y=8frac89\frac{y^2-1}y=frac{80}9\9y^2-9=80y\9y^2-80y-9=0\D=6400+4cdot9cdot9=6400+324=6724=(82)^2\y_{1,2}=frac{80pm82}{18}\y_1=-frac19,;y_2=18$

$4);y+frac3y=10frac3{10}\frac{y^2+3}y=frac{103}{10}\10y^2+30=103y\10y^2-103y+30=0\D=10609-4cdot10cdot30=10609-1200=9409=(97)^2\y_{1,2}=frac{103pm97}{20}\y_1=frac3{10},;y_2=10$