1) (am+a^2)/m^3) *(a^2/(m^2+am)=(m(m+a)/(m^3)*a^2/(m(m+a)=a^2/m^3
2. (x+x+1)/(x+1))*(1+x)/(2x-1)=(2x+1)/(2x-1)
3. (2m+1)(2m+1)-(2m-1)(2m-1))/(2m-1)(2m+1))*(5(2m+1)/4m=
(4m^2+2m+2m+1-(4m^2-2m-2m+1)/(2m-1))*5/4m=5(4m^2+4m+1-4m^2+4m-1)/4m(2m-1)=40m/4m(2m-1)=10/(2m-1)
в последнем не уверена