3/4 w - 1/2 w - 4 = 12

The answer is 64 because you add 4 to both sides then you get 3/4w-1/2w=16 then you find like terms between 3/4w and 1/2w and it's 4 so you change 1/2 to 2/4 and then subtract 2/4w from 3/4w and you get 1/4w and that would make your equation 1/4w=16 then you divided by 1/4 which is multiplying by 4 and you get W=64