X-2/X+3=(x+2/x-2)-(16/x^2-4)
X-2/X+3=x+2/x-2-16/x^2-4
X-x-2/X-2/x+16/x^2=-2-4-3
-4/x+16/x^2=-9
4/x-16/x^2=9
4x-16=9x²
9x²-4x=-16
x²-4x/9=-16/9
x²-4x/9+(2/9)²=4/81-144/81
(x-2/9)²=-140/81
实数范围内无解。
x-2/9=±√140i/9
x=2/9±√140i/9
X-2/X+3=(x+2/x-2)-(16/x^2-4)
X-2/X+3=[(x+2)²-16]/(x² -4)
(X-2)(x² -4))=[(x+2)² -16](x+3)
(X-2)(x² -4))=[(x+2) -4][x+2+4)(x+3)
(X-2)(x² -4))=(x-2)(x+6)(x+3)
x²-4=x²+9x+18
9x=-22
x=-22/9