问题
解答题
已知x=1时,ax3+bx2+cx+3=0,则x=-1时,ax3-bx2+cx+3的值为______.
答案
把x=1代入ax3+bx2+cx+3=0,
可得a+b+c=-3;
当x=-1,a+b+c=-3时,
ax3-bx2+cx+3=-a-b-c+3=-(a+b+c)+3=3+3=6.
已知x=1时,ax3+bx2+cx+3=0,则x=-1时,ax3-bx2+cx+3的值为______.
把x=1代入ax3+bx2+cx+3=0,
可得a+b+c=-3;
当x=-1,a+b+c=-3时,
ax3-bx2+cx+3=-a-b-c+3=-(a+b+c)+3=3+3=6.