SOLUTION: Solve be either the subsistution or the addition-or-subtraction method. 2m = n - 3 3m = 2n - 9 Am I suppose to change

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Question 201999This question is from textbook Algebra Structure and Method
: Solve be either the subsistution or the addition-or-subtraction method.
2m = n - 3
3m = 2n - 9
Am I suppose to change the equation to
n - 3 = 2m
3n - 9 = 3m
Or change it to an additon problem? I'm really stuck
This question is from textbook Algebra Structure and Method

Found 2 solutions by rfer, adamchapman:
Answer by rfer(16322) About Me  (Show Source):
You can put this solution on YOUR website!
2m=n-3
3m=2n-9
change one equation to terms of n=
2m=n-3
n=2m+3
substitute this for n in the other equation
3m=2(2m+3)-9
3m=4m+6-9
-m=-3 multiply through by -
m=3
-------------------------------
2(3)=n-3
6=n-3
9=n

Answer by adamchapman(301) About Me  (Show Source):
You can put this solution on YOUR website!
OK, what you need to do is mix the 2 equations together into one expression.

do this by subtracting one from the other, everything on the left hand side together and then everything on the right hand side of the "=" sign. It is very important to keep terms on the same side.
2m+-+3m+=++n+-+3++-+2n+%2B+9
which simplifies to
-m+=+-n+-+12
or
2m+=+-27+%2B+12
so m=-7.5
Hope you can go through this and make sens of it,
Adam
now plug this in to the first equation (2m = n - 3 ):
+2n+%2B+24+=+n-3
which solves to give
n=-27
replace n with -27 in your first equation again to get
+m+=+n-3