化简：1.X²-4/X²+4X+4÷(X-2)×(X+1)(X+2)/X-22.1/X(X+1)+1/(X+1)(X+2)+1/(X+2)(X+3)3.X-9Y/6XY²-X+3Y/9X²Y

化简：1.X²-4/X²+4X+4÷(X-2)×(X+1)(X+2)/X-22.1/X(X+1)+1/(X+1)(X+2)+1/(X+2)(X+3)3.X-9Y/6XY²-X+3Y/9X²Y
化简：1.X²-4/X²+4X+4÷(X-2)×(X+1)(X+2)/X-2
2.1/X(X+1)+1/(X+1)(X+2)+1/(X+2)(X+3)
3.X-9Y/6XY²-X+3Y/9X²Y

化简：1.X²-4/X²+4X+4÷(X-2)×(X+1)(X+2)/X-22.1/X(X+1)+1/(X+1)(X+2)+1/(X+2)(X+3)3.X-9Y/6XY²-X+3Y/9X²Y
1.=...
2.=1/x-1/(x+1)+1/(x+1)-1/(x+2)+1/(x+2)-1/(x+3)=1/x-1/(x+3)=3/x(x+3);
3.=(2Y-9)/6X²Y

1.=...
2.=1/x-1/(x+1)+1/(x+1)-1/(x+2)+1/(x+2)-1/(x+3)=1/x-1/(x+3)=3/x(x+3);
3.=(2Y-9)/6X²Y

3/x(x+3)
第二个写的不明白括号没有写吧