5 / 9 + 3 / 11 + 4 / 9 + 8 / 11 + 7 / 18 △ 4 + 3 / 4 × 7 / 18 (1 / 4-1 / 6) × 12 5 of 9 + 3 of 11 + 4 of 9 + 8 of 11 + 7 of 18 △ 4 + 3 of 4 × 7 of 18 (1 of 4-1 of 6) × 12 important process

5 / 9 + 3 / 11 + 4 / 9 + 8 / 11 + 7 / 18 △ 4 + 3 / 4 × 7 / 18 (1 / 4-1 / 6) × 12 5 of 9 + 3 of 11 + 4 of 9 + 8 of 11 + 7 of 18 △ 4 + 3 of 4 × 7 of 18 (1 of 4-1 of 6) × 12 important process

5 / 9 + 3 / 11 + 4 / 9 + 8 / 11
=5/9+4/9+3/11+8/11
=2
7 / 18 △ 4 + 3 / 4 × 7 / 18
=7/18x1/4+3/4x7/18
=(1/4+3/4)x7/18
=7/18
1 / 4-1 / 6) × 12
=1/4x12-1/6x12
=3-2
=1