SOLUTION: I was going along just fine doing Systems of Linear Equations and inequalities by the addition method. All of a sudden I had fractions and I am so confused, I have come up with the

Question 12587: I was going along just fine doing Systems of Linear Equations and inequalities by the addition method. All of a sudden I had fractions and I am so confused, I have come up with the answers for a few of them, I don't know how, I just kept trying different things to multiply them by, but there has got to be something I am doing wrong. It is taking me 4 hours to do 20 problems and a whole sheet of paper just to answer 3 problems. Here is one I got to and completely went, HUH!!
2x/5 - y/2=13/2
3x/4 - y/5=17/2
Now, If i remember right, my instructor said that you wanted to find a number to multiply these all by, and to find a number that all 3 denominators would go into. So I used 10 for the 1st one. This is how I did it.
(10)2x/5 - (10)y/2=(10)13/2, and my answer for that one is
4x+5y=65, I don't know if this is right, or if it is, what to do next. Please Help!!!!!!!!!! Thank you!
Answer by Earlsdon(6103) (Show Source):
You can put this solution on YOUR website!
You are on the right track! Multiply the 1st equation by 10.

Multiply the 2nd equation by 20.

So, now you have:
and
Now you can solve these by any one of the accepted methods so let's try elimination.
Let's multiply the 1st equation by 4 (so we can get 20y) and the 2nd equation by 5 (so we can get 20y there too}. Then we'll subtract one equation from the other to eliminate the y terms.

Subtract the top one from the bottom one.
---------------------
Divide both sides by 59.

From: rewrite as: and substitute x = 10 and solve for y.

Divide both sides by 5.

The solution is: (10, -5)
Let's see what the graph looks like: