1.若把x²-8x+m分解因式得(x-5)(x+n),求m,n的值 2.已知m²+n²+6m-10n+34=0(m+n)²(m-n)²-(m-n)(m+n)(m²+n²)的值

问题描述:

1.若把x²-8x+m分解因式得(x-5)(x+n),求m,n的值 2.已知m²+n²+6m-10n+34=0
(m+n)²(m-n)²-(m-n)(m+n)(m²+n²)的值

1.x^2-8x+m=(x-5)(x+n)
x^2-8x+m=x^2-(5-n)-5n
对比系数得:
5-n=8
-5n=m
解得:
n=-3
m=15
2.m²+n²+6m-10n+34=0
(m²+6m+9)+(n²-10n+25)=0
(m+3)^2+(n-5)^2=0
解得
m+3=0
n-5=0
m=-3
n=5