6а+1/(2а+1)(2а-1) - 2а/-2а-1

Question

6а+1/(2а+1)(2а-1) - 2а/-2а-1

Answer 1

6a+1/(2a+1)(2a-1)+2a/(2a+1)=(6a+1)/(4a^2-1)+2a(2a-1)/4a^2-1=(6a+1+4a^2-2a)/(4a^2-1)=
=4a+1+4a^2/4a^2-1=(2a+1)^2/(2a-1)(2a+1)=2a+1/2a-1