Question 1189782
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In the future, please post <u>full</u> instructions to the problem. 


If you want to solve for m, then,
m+2n = 3
m = 3-2n
I subtracted 2n from both sides to undo the +2n


Or if you want to solve for n, then
m+2n = 3
2n = 3-m
n = (3-m)/2
We first subtract off m, then divide both sides by 2. Effectively, I'm following PEMDAS in reverse.
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