A) a-12/2(a-4) + a/a-4 = a-12 +2a/2(a-4) = 3a - 12/2(a-4)=3(a-4)/2(a-4)=3/2=1.5
б) x-1/3(x-4) - x-2/2(x-4)=2(x-1) - 3(x-2) / 6(x-4)=2x-2-3x+6/ 6(x-4)= - x +4/6(x-4)= - (x-4)/6(x-4)= - 1/6
в) у-27/2(3-у) + 4у/3-у= y-27+8y/2(3-y)=9y-27/2(3-y)= - 9(3-y)/2(3-y)= - 4/5
г) с-2/2(3с+2) - с-6/5(3с+2) = 5с-10 -2с+12/10(3с+2)=3с+2/10(3с+2)=1/10