А) 9,2a-x+3x-8a-7a+6,3a=а) 9,2a-8a-7a+6,3a-х+3х=0,2а+2х
б) 8,2m•(-m+m2-4m2-9,6m2)=-8,2m^2+8,2m^3-32,8m^3-78,72m^3=
-8,2m^2-103,32m^3=-8,2m^2(1+12,6m)
в) 2n•n•n-9n3-7,1 n3-15n3=2n^3-9n^3-7,1n^3-15n^3=n^3(2-9-7,1-15)=-29,1n^3
ж) -3,8r-a+3,8r-9a+a2=-3,8r+3,8r-a-9a+a^2=a^2-10a=a(a-10)