3的2m-4n+1次方
=3^2m÷3^4n×3
=(3^m)^2÷(9^n)^2×3
=6^2÷2^2×3
=36÷4×3
=27是-2n的次方!...=3^2m ÷ 3^2n x 3²=(3^m)^2 ÷9^n x 9=6²÷2 x 9=36 ÷2 x9=162