2,6x-[1,8y-[2,2x-y]+1,4y]-[1,6x-0,2y]=

2,6x-[1,8y-[2,2x-y]+1,4y]-[1,6x-0,2y]= 2,6x-1,8y+2,2x-y-1,4y-1,6x+0,2y= 3,2x-4y

2,6x-[1,8y-[2,2x-y]+1,4y]-[1,6x-0,2y]= 2,6x - [1,8y - 2,2x + y +1,4y] - 1,6x +0,2y= 2,6x - [ 4,2y -2,2x] -1,6x + 0,2y= 2,6x - 4,2y + 2,2x -1,6x + 0,2y = 3,2x -4y