\frac{\frac{v-u}{1-\frac{vu}{c^2}}+\frac{w-v}{1-\frac{wv}{c^2}}}{1+\frac{\frac{v-u}{1-\frac{vu}{c^2}}\cdot \frac{w-v}{1-\frac{wv}{c^2}}}{c^2}}=\frac{w-u}{1-\frac{wu}{c^2}}