Verify whether the given statement is true or false:

$\left(\dfrac{-3}{5} \div \dfrac{-12}{35}\right) \div \dfrac{1}{4} = \dfrac{-3}{5} \div \left(\dfrac{-12}{35} \div \dfrac{1}{4}\right)$

Solve the L.H.S. and the R.H.S. separately by first simplifying the bracket, and then compare them.

Solving L.H.S.,

$\Rightarrow \dfrac{-3}{5} \div \dfrac{-12}{35} = \dfrac{-3}{5} \times \dfrac{35}{-12} \\[1em] \Rightarrow \dfrac{(-3) \times 35}{5 \times (-12)} = \dfrac{-105}{-60} = \dfrac{7}{4} \\[1em] \therefore \left(\dfrac{-3}{5} \div \dfrac{-12}{35}\right) \div \dfrac{1}{4} = \dfrac{7}{4} \div \dfrac{1}{4} \\[1em] \Rightarrow \dfrac{7}{4} \times \dfrac{4}{1} = 7$

Solving R.H.S.,

$\Rightarrow \dfrac{-12}{35} \div \dfrac{1}{4} = \dfrac{-12}{35} \times \dfrac{4}{1} = \dfrac{-48}{35} \\[1em] \therefore \dfrac{-3}{5} \div \left(\dfrac{-12}{35} \div \dfrac{1}{4}\right) = \dfrac{-3}{5} \div \dfrac{-48}{35} \\[1em] \Rightarrow \dfrac{-3}{5} \times \dfrac{35}{-48} = \dfrac{-105}{-240} = \dfrac{7}{16}$

As L.H.S. $≠$ R.H.S., division of rational numbers is not associative.

Hence, the given statement is false.