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

问题描述:

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