Express the following rational number in standard form:

$\dfrac{-14}{49}$

A rational number $\dfrac{p}{q}$ is in standard form if $q \gt 0$ and $p, q$ have no common divisor other than 1.

Here the denominator 49 is already positive.

The greatest common divisor of 14 and 49 is 7.

Now,

$\dfrac{-14}{49} = \dfrac{-14 \div 7}{49 \div 7} = \dfrac{-2}{7}$

Hence, the standard form of $\mathbf{\dfrac{-14}{49} \text{ is } \dfrac{-2}{7}}$.