帮忙分解几个分式1.(x²+9x)/(x²+3x)+(x²-9)/(x²+6x+9)2.((3x/x-2)-(x/x+2))×(x²-4/x)3.(2+(1/a-1)-(1/a+1)）÷(a-(a/1-a²),其中a=24.已知1/a+1/b=-4/a+b,求b/a+a/b
问题描述：
帮忙分解几个分式
1.(x²+9x)/(x²+3x)+(x²-9)/(x²+6x+9)
2.((3x/x-2)-(x/x+2))×(x²-4/x)
3.(2+(1/a-1)-(1/a+1)）÷(a-(a/1-a²),其中a=2
4.已知1/a+1/b=-4/a+b,求b/a+a/b
答
2题，2x-4
3题，1
4题，-6
答
1.(x^2+9x)/(x^2+3x)+(x^2-9)/(x^2+6x+9) =[x(x+9)]/[x(x+3)]+[(x-3)(x+3)]/[(x+3)^2]=(x+9)/(x+3)+(x-3)/(x+3)=[(x+9)+(x-3)]/(x+3)=(2x+6)/(x+3)=2(x+3)/(x+3)=22.[3x/(x-2)]-[x/(x+2)]*[(x^2-4)/x] [3x/(x-2)]-[x...