∵a※b=
1
a -
1
b ,
∴x※(2x+1)=
1
x -
1
2x+1 =
2x+1-x
x(2x+1) =
x+1
2 x 2 +x ,
又∵x※(2x+1)=0,
∴
x+1
2 x 2 +x =0,
解得:x=-1,
经检验得x=-1是方程的根.
故答案为:-1.
∵a※b=
1
a -
1
b ,
∴x※(2x+1)=
1
x -
1
2x+1 =
2x+1-x
x(2x+1) =
x+1
2 x 2 +x ,
又∵x※(2x+1)=0,
∴
x+1
2 x 2 +x =0,
解得:x=-1,
经检验得x=-1是方程的根.
故答案为:-1.