А) 8*28 + 48*7 = 8*4*7 + 8*6*7=8*7(4+6)=56*10=560
б) 38*150 - 45*80 = 38*3*5*10 - 9*5*8*10 = 38*5*3*10 - 3*5*8*3*10 =3*10(38*5 - 3*5*8) = 30(190-120) = 30*70 = 2100
в) 24*9 + 12*27 = 2*12*9 + 12*3*9 = 9(24+36) = 9*60 = 540
г) 46*75 - 65*30 = 2*23*5*15 - 65*30 = 23*5*30 - 65*30 = 30(115-65) = 30*50 = 1500