12а-(b-2а)= 12а -b+2a= 14a - b
(2x +3y) -(x -2y) = 2x +3y -x +2y =x +5y
5b +(-b-5) = 5b -b -5 = 4b -5
(3x -5y)+ (-3x +y) =3x -5y -3x+y =-4y
12а-(b-2а)= 12а -b+2a= 14a - b
(2x +3y) -(x -2y) = 2x +3y -x +2y =x +5y
5b +(-b-5) = 5b -b -5 = 4b -5
(3x -5y)+ (-3x +y) =3x -5y -3x+y =-4y