You can put this solution on YOUR website! If the exponents are even,
(-2)^(2m) = 2^(9-m) is
the same as
2^(2m) = 2^(9-m) and
2m = 9-m
add m to each side
3m = 9
m = 3
plugging 3 for m in the original equation
(-2)^(2m) = 2^(9-m) becomes
(-2)^(2*3) ?= 2^(9-3)
(-2)^(6) ?= 2^(6)
2^6 = 2^6
So m = 3 is the solution.