$\dfrac{6}{x-1}-\dfrac{4}{x-3}=\dfrac{8}{(x-1)(3-x)}$
$⇒\dfrac{6}{x-1}-\dfrac{4}{x-3}=\dfrac{-8}{(x-1)(x-3)}$
$⇒\dfrac{6(x-3)}{(x-1)(x-3)}-\dfrac{4(x-1)}{(x-3)(x-1)}=\dfrac{-8}{(x-1)(x-3)}$
$⇒6(x-3)-4(x-1)=-8$
$⇒6x-18-4x+4=-8$
$⇒2x-14=-4$
$⇒2x=10$
$⇒x=5$
Bài còn lại làm tương tự nhé