石家庄安监局培训中心:帮忙解答初中数学题,谢谢!!!!!!

来源:百度文库 编辑:杭州交通信息网 时间:2024/03/28 18:25:06
当:m/x-2+n/x+1=x-8/(x+1)(x-2)时,求m*n的值?
不好意思,此问题应为:m/(x-2)+n/(x+1)=(x-8)/(x+1)(x-2),求M*N

m/(x-2)+n/(x+1)=(x-8)/(x+1)(x-2)
m(x+1)+n(x-2)=x-8
(m+n)x+(m-2n)=x-8
m+n=1,m-2n=-8
m=-2,n=3
m*n=-6

m/(x-2)+n/(x+1)=x-8/(x+1)(x-2)
m(x+1)+n(x-2)=x-8
m+n=1 m-2n=-8
m=-2,n=3
所以mn=-6

m/(x-2)+n/(x+1)=(x-8)/(x+1)(x-2)
m(x+1)+n(x-2)=x-8
(m+n)x+(m-2n)=x-8
m+n=1,m-2n=-8
m=-2,n=3
m*n=-6
答:M*N的值为6。

m/x-2+n/x+1=x-8/(x+1)(x-2) 这题要更精确的表达.
是m/(x-2)+n/(x+1)=(x-8)/(x+1)(x-2) 还是(m/x)-2+(n/x)+1=x-[8/(x+1)(x-2) ]