$\dfrac{x}{5}=\dfrac{2}{5}$
$→x=2$
Vậy $x=2$
$\dfrac{3}{x-5}=\dfrac{-4}{x+2}$ (với $x\neq5;x\neq-2$)
$-4(x-5)=3(x+2)$
$-4.x-(-4).5=3.x+3.2$
$-4x+20=3x+6$
$-4x-3x=6-20$
$-7x=-14$
$x=2$ (nhận)
Vậy $x=2$
$\dfrac{5}{9}+\dfrac{x}{-1}=\dfrac{-1}{3}$
$\dfrac{x}{-1}=\dfrac{-1}{3}-\dfrac{5}{9}$
$\dfrac{x}{-1}=\dfrac{-8}{9}$
$x=\dfrac{(-8).(-1)}{9}$
$x=\dfrac{8}{9}$
Vậy $x=\dfrac{8}{9}$
$1-x=\dfrac{49}{65}.\dfrac{5}{7}$
$1-x=\dfrac{49.5}{65.7}$
$1-x=\dfrac{7}{13}$
$x=1-\dfrac{7}{13}$
$x=\dfrac{6}{13}$
Vậy $x=\dfrac{6}{13}$