you would do 4×4 and get 16(20-x)-8(x+3)=8 so then × 16 by 20 and 16 by x and get 320-16x and then × -8 by x and -8 by 3 and get -8x-24 so then you would have 320-16x--8x-24=8 then - -8x from -8x and -16x and end up with 320-8x-24=8 then subtract 320-24 and get 296 and then have 296-8x=8 then subtract 296 on both sides and you will get -8x=288 then divide -8 on both sides and x= 37