a = 50 + 9 : 9 - 45
a = 50 + 1 - 45
a = 51 - 45
a = 6
b = 3 × 300 - 55 × 5 × 2 + 3 - 14 : 7 - 5 × 0
b = 900 - 550 + 3 - 2 - 0
b = 350 + 3 - 2 - 0
b = 353 - 2 - 0
b = 351 - 0
b = 351
c = 35 × 2 + 45 × 3
c = 70 + 135
c = 205
a × b - c = 6 × 351 - 205 = 2.106 - 205 = 1.901