1: 4 × (7 + 8 - 9)

2: 4 × ((7 + 8) - 9)

3: 4 × (7 + (8 - 9))

4: 4 × (7 - 9 + 8)

5: 4 × ((7 - 9) + 8)

6: 4 × (7 - (9 - 8))

7: 4 × (8 + 7 - 9)

8: 4 × ((8 + 7) - 9)

9: 4 × (8 + (7 - 9))

10: (4 + 8) × (9 - 7)

11: 4 × (8 - 9 + 7)

12: 4 × ((8 - 9) + 7)

13: 4 × (8 - (9 - 7))

14: (7 + 8 - 9) × 4

15: ((7 + 8) - 9) × 4

16: (7 + (8 - 9)) × 4

17: (7 - 9 + 8) × 4

18: ((7 - 9) + 8) × 4

19: (7 - (9 - 8)) × 4

20: (8 + 4) × (9 - 7)

21: (8 ÷ (7 - 4)) × 9

22: 8 ÷ (7 - 4) × 9

23: 8 ÷ ((7 - 4) ÷ 9)

24: (8 + 7 - 9) × 4

25: ((8 + 7) - 9) × 4

26: (8 + (7 - 9)) × 4

27: (8 - 9 + 7) × 4

28: ((8 - 9) + 7) × 4

29: (8 - (9 - 7)) × 4

30: 8 × (9 ÷ (7 - 4))

31: 8 × 9 ÷(7 - 4)

32: (8 × 9) ÷ (7 - 4)

33: (9 - 7) × (4 + 8)

34: (9 ÷ (7 - 4)) × 8

35: 9 ÷ (7 - 4) × 8

36: 9 ÷ ((7 - 4) ÷ 8)

37: (9 - 7) × (8 + 4)

38: 9 × (8 ÷ (7 - 4))

39: 9 × 8 ÷(7 - 4)

40: (9 × 8) ÷ (7 - 4)