a) \(\dfrac{y-2}{15}=-\dfrac{2}{3}\\ =>\left(y-2\right).3=-2.15\\ < =>3y-6=-30\\ < =>3y=-30+6\\ < =>3y=-24\\ =>y=\dfrac{-24}{3}=-8\)
Vậy: y= -8
\(\dfrac{7}{x}< \dfrac{x}{5}< \dfrac{11}{x}\\ < =>\dfrac{35}{5x}< \dfrac{x^2}{5x}< \dfrac{55}{5x}\\ =>35< x^2< 55\\ < =>35< \pm6^2< \pm7^2< 55\)
Vậy: \(x\in\left\{-7;-6;6;7\right\}\)