SOLUTION: I am suppose to solve the systems of equations by elimination and I don't understand it. Here is my problem. It says to solve by substitution. -5x+3y=12 x+2y=8

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Question 900830: I am suppose to solve the systems of equations by elimination and I don't understand it. Here is my problem. It says to solve by substitution.
-5x+3y=12
x+2y=8
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
            system%28-5x%2B3y=12%2Cx%2B2y=8%29

We look for a term in one of those equations that has a letter
with an understood coefficient of 1 or -1.

We see that x%2B2y=8 has a term x with a 1 understood 
coefficient.  

We solve for that letter by getting it alone on one side:

            x%2B2y=8

Subtract 2y from both sides
                x=8-2y

Now in the other equation -5x%2B3y=12, substitute (8-2y)
for x

           -5x%2B3y=12
           -5%288-2y%29%2B3y=12

Solve for y

           -40%2B10y%2B3y=12
           -40%2B13y=12
               13y=12%2B40
               13y=52
               13y%2F13=52%2F13
                y=4

Substitute (4) for y in the equation where you solved for x

                x=8-2y
                x=8-2%284%29
                x=8-8
                x=0

So that means that the common solution to the pair of equations
is (x,y) = (0,4) 

It means that if you draw the graphs of the two lines they will
intersect at the point (0,4)

system%28-5x%2B3y=12%2Cx%2B2y=8%29



Edwin