Verified answer

(200 − a) (80 + b) (70 + c)

= (200 − a) (80 (70 + c) + b (70 + c))

= (200 − a) (5600 + 80c + 70b + bc)

= 200 (5600 + 80c + 70b + bc) − a (5600 + 80c + 70b + bc)

= 1120000 + 16000c + 14000b + 200bc − 5600a − 80ac − 70ab − abc

= 1120000 − 5600a + 14000b + 16000c − 70ab − 80ac + 200bc − abc

(200 - a) × (80 + b) × (70 + c)

(16000 + 200b - 80a - ab) × (70 + c)

1120000 + 14000b - 5600a - 70ab + 16000c + 200bc - 80ac - abc