2 1/6 + 2 1/12:(1,64:0,8-1,375*2,4)

2 1/6 + 2 1/12 : (1,64 : 0,8 - 1,375 * 2,4) = 1/2 1) 1,64 : 0,8 = 2,05 2) 1,375 * 2,4 = 3,3 3) 2,05 - 3,3 = - 1,25 = - 1 1/4 4) 2 1/12 : (-1 1/4) = 25/12 : (-5/4) = 25/12 * (-4/5) = - (5*1)/(3*1) = - 5/3 = - 1 2/3 5) 2 1/6 + (-1 2/3) = 2 1/6 - 1 4/6 = 1 7/6 - 1 4/6 = 3/6 = 1/2