Tìm x biết

a.2x-6=0
b.x-3/x+1=x^2/x^2-1
c.(3x+3)(2x-4)=0
d.x/x+3-x/x+1=2x+8/(x+1)(x+3)
e.2/x-3+3/x+3=3x+5/x^2-9