(2x-1)^2-(4x^2-1)=0

1,(2x-1)^2-(4x^2-1)=0
2,(x+2)^2-x(x-3)=2
3,(x-5)^2-x(x+2)=5
4,(x-1)^2+x(4-x)=11
5,(x-3)(x+3)=(x-5)^2