\(\dfrac{\dfrac{2.15}{3.15}+\dfrac{2.9}{5.9}-\dfrac{2.5}{5.9}}{\dfrac{4.15}{3.15}+\dfrac{4.9}{5.9}-\dfrac{4.5}{9.5}}\)
=\(\dfrac{\dfrac{30}{45}+\dfrac{18}{45}-\dfrac{10}{45}}{\dfrac{60}{45}+\dfrac{36}{45}-\dfrac{20}{45}}\)
=\(\dfrac{\dfrac{38}{45}}{\dfrac{76}{45}}\)=1/2
\(\dfrac{2\cdot\left(\dfrac{2}{3}+\dfrac{2}{5}-\dfrac{2}{9}\right)}{\dfrac{4}{3}+\dfrac{4}{5}-\dfrac{4}{9}}\) = \(\dfrac{\dfrac{4}{3}+\dfrac{4}{5}-\dfrac{4}{9}}{\dfrac{4}{2}+\dfrac{4}{5}-\dfrac{4}{9}}\) = 1