问题 填空题

若(x2+mx+n)(x2-3x+2)中,不含x2和x3项,则m=______,n=______.

答案

∵(x2+mx+n)(x2-3x+2),

=x4-3x3+2x2+mx3-3mx2+2mx+nx2-3nx+2n,

=x4+(-3+m)x3+(2-3m+n)x2+(2m-3n)x+2n,

又∵结果中不含x2和x3项,

∴-3+m=0,2-3m+n=0,

解得:m=3,n=7.

单项选择题
多项选择题