Răspuns:
a) 17 (12 + 18) = 17 · 30 = 510
b) 22 (45 + 55) = 22 · 100 = 220
c) 24 (156 + 31 - 1) = 24 · 186 = 4464
d) 22 (511 + 489) = 22 · 1000 = 22000
e) 377 (67 + 33) = 377 · 100 = 37700
f) 13 (12 - 2 + 9) = 13 · 19 = 247
