原分式方程为
[(6y+12)/(y²+4y+4)]-[(y²-4)/(y²-4y+4)]+[y²/(y²-4)]=0
化简:
[6(y+2)/(y+2)²]-[(y+2)(y-2)/(y-2)²]+{y²/[(y+2)(y-2)]}=0
[6/(y+2)]-[(y+2)/(y-2)]+{y²/[(y+2)(y-2)]}=0
方程两边同时乘最简公分母(y+2)(y-2)
6(y-2)-(y+2)²+y²=0
6y-12-y²-4y-4+y²=0
2y-16=0
2y=16
y=8
检验:把y=8代入最简公分母
(y+2)(y-2)=(8+2)×(8-2)=60≠0
原分式方程的解为y=8