2a-(a+1)+a的平方-1的和/a-1
问题描述:
2a-(a+1)+a的平方-1的和/a-1
答
2a-(a+1)+(a²-1)/(a-1)
=2a-(a+1)+(a+1)(a-1)/(a-1)
=2a-(a+1)+(a+1)
=2a