Transpose 4 to the other side of equation.
-3x=3x-16-4(add -16-4) -3x=3x-20
Second divide both sides with -3, so the left of the equation have only x
-3x/-3=3x/-3 - 20/-3
then transpose -x to the left. add them
lastly, divide again both sides with 2.
x=10/3 >> Answer
To check the answer substitute x with 10/3 to make it equal.
-6=-6 (Equal) [=)