Simple...
4.) -8-x=x-4x
So, what you want to do is isolate x.
Which means that you must move x to one side, and any other variables to the other side.
-8-x=x-4x
-8-x=-3x
-8-x=-3x
+x +x
-8=-2x
4=x
Thus, your answer.
To check your work...plug in x.
-8-x=x-4x
-8-4=4-4(4)
-12=4-(16)
-12=-12
Thus, you know your answer is correct.
4.) -8-x=x-4x
So, what you want to do is isolate x.
Which means that you must move x to one side, and any other variables to the other side.
-8-x=x-4x
-8-x=-3x
-8-x=-3x
+x +x
-8=-2x
4=x
Thus, your answer.
To check your work...plug in x.
-8-x=x-4x
-8-4=4-4(4)
-12=4-(16)
-12=-12
Thus, you know your answer is correct.