Question

-20=-4x-6 what is x?

Answer 1

remember you can do anything to an equation as long as you do it to both sides

-20=-4x-6
add 6 to both sides
-16=-4x
divide both sides by -4
4=x
x=4

Answer 2

add 6 to  both  sides
whhich will equal to
-14=-4x
divide  -4 to both sides.
-14/-4
=3.5