【如果】
1÷(a+1)+(a-1)²÷[(a+1)(a-1)]-1
原式
=1/(a+1)+(a-1)/(a+1)-1
=a/(a+1)-1
=1/(a+1)
=1/(4+1)
=1/5
1÷a+1+（a-1）的平方÷（a+1）（a-1）-1
=1/(a+1)+(a-1)²/[(a+1)(a-1)]-1
=(1+a-1)/(a+1)-1`
=(a-a-1)/(a+1)
=-1/(a+1)
=-1/(4+1)
=-1/5
如本站内容“对您有用”，欢迎随意打赏，让我们持续更新！
