Arthimetr А) 10*(15-6) = 10*15 - 10*6 =90
Б) 5*(18-3) =5*18 - 5*3 = 75
В) (9-3)*12 = 9*12 - 3*12 = 108 - 36 = 72
Г) (91-1)*7 = 91*7 - 1*7 = 630.