Question

Простенький пример
$frac{3}{x} - frac{3}{x+4} =1$

Answer 1

$frac{3(x+4)-3x}{x(x+4)} =1 \ frac{3x+12-3x}{x^2+4x} =1 \ frac{12}{x^2+4x}=1 \ x^2+4x=12 \ x^2+4x-12=0 \ D=b^2-4ac=16-4*1*(-12)=16+ 48=64 \ x_{1} = frac{-b- sqrt{D} }{2a} = frac{-4-8}{2}=-6 \ x_{2} =frac{-b+ sqrt{D} }{2a} = frac{-4+8}{2}=2$