# What is the distance between (-7,8,4) and (-5,1,-6)?

Use distance,$d = \sqrt{{\left({x}_{2} - {x}_{1}\right)}^{2} + {\left({y}_{2} - y - 1\right)}^{2} + {\left({z}_{2} - {z}_{1}\right)}^{2}}$
$D = \sqrt{{\left(- 5 - \left(- 7\right)\right)}^{2} + {\left(1 - 8\right)}^{2} + {\left(- 6 - 4\right)}^{2}}$
$D = 3 \sqrt{17}$