Fill in the blanks:

(i) Additive inverse of $\dfrac{-5}{-12}$ = …………… .

(ii) $\dfrac{-5}{-12}$ + its additive inverse = …………… .

(iii) If $\dfrac{a}{b}$ is the additive inverse of $\dfrac{-c}{d}$, then $\dfrac{-c}{d}$ is the additive inverse of …………… .
And, so $\dfrac{a}{b} + \dfrac{-c}{d} = \dfrac{-c}{d} + \dfrac{a}{b}$ = …………… .

State, true or false:

(i) $\dfrac{7}{9} = \dfrac{7 + 5}{9 + 5}$

(ii) $\dfrac{7}{9} = \dfrac{7 - 5}{9 - 5}$

(iii) $\dfrac{7}{9} = \dfrac{7 \times 5}{9 \times 5}$

(iv) $\dfrac{7}{9} = \dfrac{7 ÷ 5}{9 ÷ 5}$

(v) $\dfrac{-5}{-12}$ is a negative rational number.

(vi) $\dfrac{-13}{25}$ is smaller than $\dfrac{-25}{13}$

The sum of two rational numbers is 8, if one of them is $2\dfrac{3}{4}$, the other number is

1. $6\dfrac{3}{4}$

2. $6\dfrac{1}{4}$

3. $5\dfrac{1}{4}$

4. $5\dfrac{3}{4}$

For three rational numbers $\dfrac{a}{b}$ , $\dfrac{c}{d}$ and $\dfrac{e}{f}$, we have:

1. $\dfrac{a}{b} - \Big(\dfrac{c}{d} - \dfrac{e}{f}\Big) = \dfrac{a}{b} - \dfrac{c}{d} + \dfrac{e}{f}$

2. $\dfrac{a}{b} - \Big(\dfrac{c}{d} - \dfrac{e}{f}\Big) = \dfrac{a}{b} - \dfrac{c}{d} - \dfrac{e}{f}$

3. $\dfrac{a}{b} + \Big(\dfrac{c}{d} + \dfrac{e}{f}\Big)$ ≠ $\Big(\dfrac{a}{b} + \dfrac{c}{d}\Big) + \dfrac{e}{f}$

4. $\dfrac{a}{b} + \Big(\dfrac{c}{d} + \dfrac{e}{f}\Big) = \Big(\dfrac{a}{b} + \dfrac{c}{d}\Big) + \dfrac{a}{b} + \dfrac{e}{f}$