The equation means that
solve for m to get the ratio of n and m
so m + 4n = 2n +8m to get the ratio of n and m you'll just add all n and all m but the other m is not known just analyze and it means that m + 4n should have the same answer to 2n + 8m so 8 + 2 = 10
just subtract 10 by 4 and you'll get 6 so the m is 6
then follow the process 6m +8m = m : 4n + 2n so the answer is
14:6 because ratios should not contain labels
