\(\frac{-7}{8}\cdot\frac{8}{9}=\frac{112}{x}\)
=> \(\frac{-7}{9}=\frac{112}{x}\)
=> \(\frac{-7}{9}=\frac{112\div\left(-16\right)}{x\div\left(-16\right)}\)
=> \(9=x\div\left(-16\right)\)
=> \(x=-144\)
Hoặc : \(-7x=9\cdot112\)
=> \(-7x=1008\)
=> \(x=-144\)