Add and express the sum as a mixed rational number if required:

$\frac{1}{2}+\frac{1}{3}+\frac{-2}{5}$

Add and express the sum as a mixed rational number if required:

$\frac{1}{3}+\frac{3}{4}+\frac{-4}{5}$

Add and express the sum as a mixed rational number if required:

$\frac{2}{3}+\frac{2}{5}+\frac{-7}{15}$

Add and express the sum as a mixed rational number if required:

$\frac{3}{5}+\frac{3}{10}-\frac{7}{15}$

Represent the following addition on the number line:

$\frac{1}{3}+\frac{2}{3}$

Represent the following addition on the number line:

$\frac{3}{5}+\frac{4}{5}$

Represent the following addition on the number line:

$\frac{2}{3}+1\frac{1}{3}$

Represent the following addition on the number line:

$\frac{2}{3}+\frac{5}{-3}$

Subtract $\frac{-7}{15}$ from $\frac{-6}{15}$