Using commutativity and associativity of addition of rational numbers, express each of the following as a rational number:
(i)`2/5+7/3+(-4)/5+(-1)/3`

(ii) `3/7+(-4)/9+(-11)/7+7/9`

Explanation

Let's solve the given problems step by step.

### (i) \( \frac{2}{5} + \frac{7}{3} + \left(-\frac{4}{5}\right) + \left(-\frac{1}{3}\right) \)

**Step 1: Group the terms with the same denominator.**
We can group the terms with the same denominator:
\[
\left(\frac{2}{5} + \left(-\frac{4}{5}\right)\right) + \left(\frac{7}{3} + \left(-\frac{1}{3}\right)\right)
...