问题
填空题
已知(x2+mx+n)(x2-3x+2)的展开式中不含x2项和x项,则m=______,n=______.
答案
(x2+mx+n)(x2-3x+2)=x4-(3-m)x3+(2+n-3m)x2+(2m-3n)x+2n,
∵(x2+mx+n)(x2-3x+2)的展开式中不含x2项和x项,
则有
,2+n-3m=0 2m-3n=0
解得
.m= 6 7 n= 4 7
故答案为:
,6 7
.4 7