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.
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.
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.