x=-2时,代数式ax5+bx3+cx-6的值为8,求当x=2时,代数式ax5+bx3+cx-6的值.
问题描述:
x=-2时,代数式ax5+bx3+cx-6的值为8,求当x=2时,代数式ax5+bx3+cx-6的值.
答
当x=-2时,-25a-23b-2c-6=8得到25a+23b+2c+6=-8,
所以25a+23b+2c=-8-6=-14
当x=2时,ax5+bx3+cx-6=25a+23b+2c-6=(-14)-6=-20