Answer:

1. n = 8

2. n = 56

3 n = 39

4 n = 22

5 n = 39

Explanation:

1 ). (12 + 3) - 7 = n

(15) - 7 = n

15 - 7 = n

n = 8

2 ). 4 (6 + 8) = n

4 (14) = n

4 • 14 = 56

n = 56

3 ). 25 + 5 + 9 = n

39 = n

n = 39

4 ). ( 18+4 ) + ( 5+3 ) = n

(14) + (8) = n

14 + 8 = n

22 = n

n = 22

5 ). (6 + 3) + (10 • 3) = n

(9) + (30) = n

9+ 30 = n

39 = n

n = 39