Question

помогите решит уровнение ​

Answer 1

$displaystyle tt 1). frac{18}{x}-frac{46}{x-5}=1\\{} 18cdot(x-5)-46x=x^{2}-5x\\{} x^{2}+23x+90=0 D=b^{2}-4ac=169=13^{2}\\{} x_{1,2}=frac{-bбsqrt{D}}{2a}\\{} x_{1}=-5\\{} x_{2}=-18$

Ответ: {-5; -18}

$displaystyle tt 2). left { {{7x-y=5} atop {xy=18 }} right. <=> left { {{y=7x-5 } atop {x(7x-5)=18}} right.\\\{} 7x^{2}-5x-18=0 D=b^{2}-4ac=25+504=529=23^{2}\\{} x_{1,2}=frac{-bбsqrt{D}}{2a}\\{} x_{1}=2 y_{1}=9\\{} x_{2}=-1frac{2}{7} y_{2}=-14$

Ответ: {2; 9}, {-1 2/7; -14}