数学问题:如果36x^2+(m-1)xy+25y^2是一个完全平方式,求m的值.

来源:百度知道 编辑:UC知道 时间:2024/05/22 16:26:30
写明过程,谢谢拉 ^_^

若36x^2+(m-1)xy+25y^2
=(6x+5y)^2
=36x^2+60xy+25y^2
m-1=60
m=61
若36x^2+(m-1)xy+25y^2
=(6x-5y)^2
=36x^2-60xy+25y^2
m-1=-60
m=-59

36x^2+(m-1)xy+25y^2
=(6x)^2+60xy+(5y)^2+(m-1-60)
=(6x+5y)^2+(m-1-60)

已知上式为平方式,则 m-1-60=0.
m=61

36x^2+(m-1)xy+25y^2=(6x+5y)^2=36x^2+60xy+25y^2
m-1=60
m=61

a平方=36,b平方=25
2ab=m-1
a=6,b=5
m-1=2*5*6=60
m=61