问题 解答题

已知当x=2时,代数式ax5+bx3+cx+3的值是8,求当x=-2时,ax5+bx3+cx+3的值.

答案

把x=2代入代数式ax5+bx3+cx+3;

得32a+8b+2c+3=8,

所以32a+8b+2c=5;

把x=-2代入代数式

ax5+bx3+cx+3

=-32a-8b-2c+3

=-(32a+8b+2c)+3

=-5+3

=-2.

单项选择题
单项选择题