А(b+c)=ab+ac
a(b-c)=ab-ac
a)57.48*0.9093+42.52*0.9093=0.9093(57.48+42.52)=0.9093*100=90.93
б) 6.395*835.67+6.395*164.33=6.395(835.67+164.33)=6.395*1000=6395
в) 104.76*378.91-94.76*378.91=378.91(104.76-94.76)=378.91*10=3789.1
г) 0.78*496.6-396.6*0.78=0.78(496.6-396.6)=0.78*100=78