x的3n+1次方×x+3x的n+一次方×x的2n+1次方=几
问题描述:
x的3n+1次方×x+3x的n+一次方×x的2n+1次方=几
答
=x^(3n+1+1)+3x^(n+1+2n+1)
=x^(3n+2)+3x^(3n+2)
=4x^(3n+2)