Draw a number line and mark

$\dfrac{3}{4}, \dfrac{7}{4}, \dfrac{-3}{4}$ and $\dfrac{-7}{4}$ on it.

Draw a number line as shown below:

In this number line

OA = AB = ……………= OA' = A'B' = 1 unit

Since the denominator of each given rational number is 4, divide each OA, AB, BC, OA', A'B',etc into four equal parts.

To represent $\dfrac{1}{4}$, move one step towards the right side of 0 to reach P as shown.

As, OA = 1 unit, therefore OP = $\dfrac{1}{4}$ unit.

Hence, to represent $\dfrac{3}{4}$, move 3 steps towards the right side of 0 to reach point Q. So, Q represent $\dfrac{3}{4}$.

In the same way to represent $\dfrac{-3}{4}$, move 3 steps towards the left side of 0 to reach point R. So, R represent $\dfrac{-3}{4}$.

So, S represent $\dfrac{7}{4}$ and T represent $\dfrac{-7}{4}$.