cipa2907 1 2/3 - 5/14 + (1 3/4 - 1/12)×4/21=1 79/126
1) 1 3/4 - 1/12 = 1 9/12 - 1/12=1 8/12
2) 1 8/12 × 4/21 = 20/63
3) 1 2/3 -5/14= 1 28/42 - 15/42= 1 13/42
4) 1 13/42 + 20/63= 1 39/126+ 40/126= 1 79/126