3x三次方2x二次方-{5x-2-[6-2x-(-x二次方+3x三次方)]
=6X^5-[5X-2-6+2X+(-X^2+3X^3)]
=6X^5-(7X-8-X^2+3X^3)
=6X^5-3X^3+X^2-7X+8
X=1
则6X^5-3X^3+X^2-7X+8
=6-3+1-7+8
=5^是甚么意思就是“次方”的意思，比如a的3次方就是a^3望采纳！