Verify commutative property of addition for the following pairs of rational numbers:

$\frac{-2}{-5}$ and $\frac{1}{3}$

Verify commutative property of addition for the following pair of rational numbers:

$\frac{9}{11}$ and $\frac{2}{13}$

Find the additive inverse of $\frac{2}{-3}$.

Find the additive inverse of $\frac{-7}{-12}$

Verify that $-(-x)=x$ for $x=\frac{10}{13}$

Verify that $-(-x)=x$ for $x=-\frac{15}{17}$.

Using appropriate properties of addition, find the following:

$\frac{4}{5}+\frac{11}{7}+\frac{-7}{5}+\frac{-2}{7}$

Using appropriate properties of addition, find the following:

$\frac{3}{7}+\frac{4}{9}+\frac{-5}{21}+\frac{2}{3}$

Write the result in mixed fraction.

$\left(\frac{-4}{9}\right)+\left(\frac{2}{7}\right)$ is a _____ number