已知(x+my)(x+ny)=x^2+2xy-8y^2.试求m^2n+mn^2的值

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 11:18:30

已知(x+my)(x+ny)=x^2+2xy-8y^2.试求m^2n+mn^2的值
已知(x+my)(x+ny)=x^2+2xy-8y^2.试求m^2n+mn^2的值

已知(x+my)(x+ny)=x^2+2xy-8y^2.试求m^2n+mn^2的值
(x+my)(x+ny)
=x^2+(m+n)xy+mny^2
=x^2+2xy-8y^2
所以
m+n=2
mn=-8
m^2n+mn^2
=mn(m+n)
=-8*2
=-16