Bạn tham khảo:
a) $\dfrac{-84}{14} < x < \dfrac{108}{9}$
$⇔ -6 < x < 12$
$⇒ x =$ { $-5; -4; -3; -2; -1; 0 ; 1; 2;3;4;5;6;7;8;9;10;11$}
b) $\dfrac{-x}{4} = \dfrac{-9}{x}$
$⇔ x² = 36 $
$⇔ x = ±6$
c) $\dfrac{111}{37} < x < \dfrac{91}{13}$
$⇔ 3 < x < 7$
$⇒ x =$ { $4; 5; 6$ }