p. 9+8 × [7+6× (5+4x 3) - 21-10 x 10
q. 401-603:3+ [330:3 +2× (0:99 + 2× 40)]: 9
r. (36:4+ 4 x 6 +8:2+2): [(36:4+3 x 13) - 3 × 10 -15]
s. 120-40:8 x [424:4-111:3+ (256 + 46:2):3]:10
s. [(6+6x9-88:8) - (3 x 7+5-63-3)-41-4