【(x的n+1次方)的四次方*x²】/【(x的n+2次方)的³/(x²)的n次方
=x的4n+4×x²÷(x的3n+6次方)×x的2n次方
=x的4n+6次方÷(x的3n+6次方)×x的2n次方
=x的n次方*x的2n次方
=x的3n次方