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M + 2n - 4m - 6m + n *combine like terms ^m - 4m - 6m + 2n + n^ ^9m + 3n^ *since the variables are not the same, you should not add the numbers. ~the answer is 9m+3n
You can get the answer by combining the like terms 
but if you have unlike signs, you just need to subtract it but you will have a negative but you can only have a negative if the higher number has the minos sign is for example -15m+5m= -10m okay

about the answer it is -9m+3n