4280185+(89040•705-478760):8=

4280185 + (89040 * 705 – 478760) : 8 = 12066990

89040 * 705 = 6277320062773200 – 478760 = 6229444062294440 : 8 = 77868054280185 + 7786805 = 12066990

1.

89040 × 705 = 62773200

2.

62773200 - 478760 = 62294440

3.

62294440 : 8 = 7786805

4.

4280185

4280185 + 7786805= 12066990.