Question

设3x的三次方-x=1,求9x的四次方+12x的三次方-3X的平方-7X+2001的值

要有过程，谢谢！~

Answer 1

3x³-x=1

原式=(9x^4-3x²)+12x³-7x+2001
=3x(3x³-x)+12x³-7x+2001
=3x×1+12x³-7x+2001
=3x+12x³-7x+2001
=12x³-4x+2001
=4(3x³-x)+2001
=4×1+2001
=2005