已知m²-5m-1=0,求2m²-5,+1/m²的值
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/21 04:30:11
![已知m²-5m-1=0,求2m²-5,+1/m²的值](/uploads/image/z/3812229-45-9.jpg?t=%E5%B7%B2%E7%9F%A5m%26%23178%3B-5m-1%3D0%2C%E6%B1%822m%26%23178%3B-5%2C%2B1%2Fm%26%23178%3B%E7%9A%84%E5%80%BC)
x){}KsՔ
-uMsu
m
tml2hC9g;m̍3Fb5ئ0 <[
&P*``Y`b~PF6yv Fsq
已知m²-5m-1=0,求2m²-5,+1/m²的值
已知m²-5m-1=0,求2m²-5,+1/m²的值
已知m²-5m-1=0,求2m²-5,+1/m²的值
m^2-5m-1=0
m^2-5m=1
m^2-5m-1=0
m-5-1/m=0
m-1/m=5
m^2+1/m^2
=(m-1/m)^2+2
=5^2+2
=25+2
=27
2m^2-5m+1/m^2
=m^2-5m+m^2+1/m^2
=1+27
=28