Evaluating, $$2 
abla 5 = \dfrac{2 + 5}{1 + 2 \times 5} = \frac{7{11}}.$$
If $a>0$ and $b>0,$ a new operation $
abla$ is defined as follows: $$a 
abla b = \dfrac{a + b}{1 + ab}.$$For example, $$3 
abla 6 = \frac{3 + 6}{1 + 3 \times 6} = \frac{9}{19}.$$Calculate $2 
abla 5.$