Since $\frac{y^{2}-2y}{y^{2}-7y-18}$ and $\frac{9\left(y-2\right)}{y^{2}-7y-18}$ have the same denominator, subtract them by subtracting their numerators.
Since $\frac{y^{2}-2y}{y^{2}-7y-18}$ and $\frac{9\left(y-2\right)}{y^{2}-7y-18}$ have the same denominator, subtract them by subtracting their numerators.
