Ответы:
1) 10.000-135.912:168+2.400*80= 10.000 - 0.808 + 192 = 10.191,192
2) (31.850-365*50):32-365= (31.850 - 18.250):32 - 365 = 13.600:32 - 365 = 425 - 365 = 60
3) (700.680-570*991):503+809= (700.680 - 565.170):503 + 809 = 135.510:503 + 809 = 269 + 809 = 1.078