To solve this expression, we need to follow the order of operations:

Simplify within parentheses:

735 - 184 = 551

Perform multiplication and division from left to right:

55440 ÷ 90 = 616
10460 ÷ 20 = 523

Perform addition and subtraction from left to right:

616 - 523 = 93
551 x 80 = 44080

Perform addition and subtraction from left to right:

93 + 900100 = 900193
900193 - 44080 = 856113

Therefore, 55440 ÷ 90 - 10460 ÷ 20 + 900100 - (735 - 184) × 80 = 856113.