-1/4 (x-8)+1/2 (x+2)=x-3
multiply both sides by 4
-(x-8) + 2(x+2) = 4(x-3)
expand the brackets
-x + 8 + 2x + 4 = 4x - 12
put the x-terms on one side and the constant values on the other
-x + 2x - 4x = -12 - 8 - 4
add all terms together
-3x = -24
divide both sides by -3
x = 8