Пошаговое объяснение:
253. 1) (238+416) - 519 = 654 - 519 = 135
2) (823-374) + (3477-3086) = 449 + 391 = 840
3) (15+12)*(15-12) = 27*3 = 81
4) (209+193):(42930 - 42924) = 402:6 = 67
254. 1) (238-149) + 506 = 89 + 506 = 595
2) (48+16):(48-16) = 64:32 = 2
3) (124+126)*(313-307) = 250*6 = 1500
4) 32*15 - 896:28 = 480 - 32 = 448
