We simplify the equation to the form, which is simple to understand 
7x-1/2(8x+4)=6
Simplifying:
7x-0.5*(8x+4)=6
Reorder the terms 
7x+(-4x-2)=6
Remove unnecessary parentheses
+7x-4x-2=+6
We move all terms containing x to the left and all other terms to the right. 
+7x-4x=+6+2
We simplify left and right side of the equation. 
+3x=+8
We divide both sides of the equation by 3 to get x. 
x=2.66666666667