4^m*8^(m-1)÷2^m=32
(2^2)^m*(2^3)^(m-1)÷2^m=32
2^2m*2^(3m-3)÷2^m=32
2^(2m+3m-3-m)=2^5
2m+3m-3-m=5
m=2