n+2=√(9+n²+2n+1) ..

来源：学生作业学帮网编辑：学帮网时间：2024/05/28 09:32:24

n+2=√(9+n²+2n+1) ..

n+2=√(9+n²+2n+1)
（n+2）²=9+n²+2n+1
n²+4n+4=9+n²+2n+1
n²+4n+4-9-n²-2n-1=0
2n-6=0
2n=6
n=3