Answer :

You need to combine like terms. So first you have to add the negative number which are -4x and -6x which equals -10x. So the problem is now -20=-10x. Finally use inverse operation to get x by itself. So x=2.
AL2006
Watch carefully . . . this could get really tricky:

-20 = -4x -6x

Do you see the  -4x  and the  -6x  on the right side ?
I'll bet if it said  (4 negative cows)  and  (6 negative cows), you'd know
right away that you could combine them into  (10 negative cows).

-4x - 6x = -10x

So now the equation is    -20 = -10x

Multiply each side by  -1 :  20 = 10x

Divide each side by  10 :    2  =  x

and there you have it.