$\frac{3}{2x+1}$ +$\frac{10}{4x+2}$ -$\frac{6}{6x+3}$ =$\frac{12}{26}$
=>$\frac{3}{2x+1}$ +$\frac{5.2}{2(2x+1)}$ -$\frac{3.2}{3(2x+1)}$ =$\frac{12}{26}$
=>$\frac{3}{2x+1}$ +$\frac{5}{2x+1}$ -$\frac{2}{2x+1}$ =$\frac{12}{26}$
=>$\frac{6}{2x+1}$ =$\frac{12}{26}$
=>$6.26$=$(2x+1).12$
=>$156$=$(2x+1).12$
=>$(2x+1).12$=$156$
=>$2x+1$=$13$
=>$2x$=$13-1$
=>$2x$=$12$
=>$x$=$6$