原式=2x/(x^2-4)-1/(2-x)+3/(x+2)
=2x/(x-2)(x+2)+1/(x-2)+3/(x+2)
=[2x+(x+2)+3(x-2)]/(x-2)(x+2)
=(6x-4)/(x-2)(x+2)
=2(3x-2)/(x-2)(x+2)
原式=2x/(x^2-4)-1/(2-x)+3/(x+2)
=2x/(x-2)(x+2)+1/(x-2)+3/(x+2)
=[2x+(x+2)+3(x-2)]/(x-2)(x+2)
=(6x-4)/(x-2)(x+2)
=2(3x-2)/(x-2)(x+2)