Need help with this complex number equation.

8-3i/-4-6i=

I am sure you meant

(8-3i)/(-4 - 6i)

multiply top and bottom by (-4+ 6i)
(8-3i)/(-4 - 6i)* (-4+ 6i)/ (-4+ 6i)
= (-32 + 48i + 12i - 18i^2)/(16 - 36i^2)
= (-32 + 60i + 18)/(16+36)
= (-14 + 60i)/52
= (-7 + 30i)/26 or -7/26 + 30i/26