(756 + 375) - 256 = (756 - 256) + 375 = 500 + 375 = 875
286 + 43 + 375 + 14 = (286 + 14) + (375 + 43) = 300 + 418 = 718
837 - (237 + 48) = (837 - 237) + 48 = 600 + 48 = 648
(120 - 20) * 4 - 1 = 100*4 - 1 = 400 - 1 = 399
(120 - 20) * (4 - 1) = 100 * 3 = 300
120 - 20 * (4 - 1) = 120 - 20*3 = 120 - 60 = 60