How do you find the distance between coordinates D (-4,-3) and E(5,9)?

The required distance is $15$ unit
Distance formula is $D = \sqrt{{\left({x}_{2} - {x}_{1}\right)}^{2} + {\left({y}_{2} - {y}_{1}\right)}^{2}}$
The distance between $D \left(- 4 , - 3\right) \mathmr{and} E \left(5 , 9\right)$ is $\sqrt{{\left(5 + 4\right)}^{2} + {\left(9 + 3\right)}^{2}} = \sqrt{81 + 144} = \sqrt{225} = 15$ unit [Ans]