(4 2/3-5/9×2 4/7)+(2 1/7+1 2/3)
1) 5/9 * 2 4/7 = 5/9 * 18/7 = 90/ 63 = 30/21 = 10/7 = 1 3/7
2) 4 2/3 - 1 3/7 = 14/3 - 10/7 = 98/21 - 30/21 = 68/21 = 3 5/21 = 3 5/21
3) 2 1/7 + 1 2/3 = 15/7 + 5/3 = 45/21 + 35/21 = 80/21 = 3 17/21
4) 3 5/21 + 3 17/21 = 6 22/21 = 7 1/21