1.已知:a/b=c/d=3,求(a+b/b)+(c-d/c+d)的值.
问题描述：
1.已知:a/b=c/d=3,求(a+b/b)+(c-d/c+d)的值.
2.化简求值：（2x/x²-x-2）÷（x/x+1）-（x+2/x²-4）,其中x=3.
答
1.原式=(3b+b)/b+(3d-d)/(3d+d)=4+1/2=9/2
2.原式=2x/(x-2)(x+1)*(x+1)/x-(x+2)/(x+2)(x-2)
=2/(x-2)-1/(x-2)
=1/(x-2)
=1/(3-2)
=1