a的m次方等于2,a的n次方等于3
a^m=2 ,a^n=3
a的2m加3n的次方
=a^(2m+3n)
=a^2m *a^3n
=2^2 *3^3
=108
a的2m减3n的次方
=a^(2m-3n)
=a^2m /a^3n
=2^2 /3^3
=4/27