x . ($\frac{1}{3.4}$ + $\frac{1}{4.5}$ + $\frac{1}{5.6}$ + ... + $\frac{1}{9.10}$) = $\frac{-14}{45}$
x . ($\frac{1}{3}$ - $\frac{1}{4}$ + $\frac{1}{4}$ - $\frac{1}{5}$ + ... + $\frac{1}{9}$ - $\frac{1}{10}$) = $\frac{-14}{45}$
x . ($\frac{1}{3}$ - $\frac{1}{10}$) = $\frac{-14}{45}$
x . ($\frac{10}{30}$ - $\frac{3}{30}$) = $\frac{-14}{45}$
x . $\frac{7}{30}$ = $\frac{-14}{45}$
x = $\frac{-14}{45}$ : $\frac{7}{30}$
x = $\frac{-14}{45}$ x $\frac{30}{7}$
x = $\frac{-4}{3}$.