x的3n次方×x+3x的n+一次方×x的2n+1次方=几
问题描述：
x的3n次方×x+3x的n+一次方×x的2n+1次方=几
x的3n+1次方×x+3x的n+一次方×x的2n+1次方=几 上面打
答
x^3n*x+3x^(n+1)*x^(2n+1)
=x^(3n+1)+3*x^(2n+2)
=x^(3n+1)*(1+3x)问题补充！！！x^(3n+1)*x+3x^(n+1)*x^(2n+1)是这样吗？=x^(3n+2)+3*x^(3n+2)=4*x^(3n+2)