若分式2(x-3)/x2+3的值为0,则2x/x2-1÷2x/1-x的值为_______.
问题描述:
若分式2(x-3)/x2+3的值为0,则2x/x2-1÷2x/1-x的值为_______.
答
∵2(x-3)/﹙x²+3﹚=0,
∴x=3
∴2x/﹙x²-1﹚÷2x/﹙1-x﹚
=﹛2x/﹙x²-1﹚﹜×﹛﹙1-x﹚/2x﹜
=﹙1-x﹚/﹛﹙x-1﹚﹙x+1﹚﹜
=﹣1/﹙x+1﹚
=﹣1/4