(1/2+2/3):5/6-12×(1/2-2/3)
7/6 * 6/5 - 12 * (-1/2) = 7/5 + 2 = (7+10)/5 = 17/5 = 3,4
1)1/2 +2/3 =3/6 +4/6 =7/6 2)7/6 :5/6 =7/6 *6/5 = 7/5 3)1/2 -2/3 =3/6 -4/6 = -1/6 4)12*(- 1/6)= -2 5)7/5 -(-2) =7/5 +2 = 7/5 +10/5 =17/5= 3 2/5