2. 2/3 ÷ 1 7/9+ 55/84÷(43/63-25/36)= -53.1/2
1) 2. 2/3 ÷ 1 7/9 = 8/3 :16/9 = 8/3*9/16=3/2=1.1/2
2) 43/63-25/36 = 172/252 - 175/252=-3/252=-1/84
3) 55/84 : (-1/84) = -55/84 * 84= -55
4) 1.1/2 + (-55) = -54.2/2 +1.1/2 = -53.1/2
