SOLUTION: The problem is this: 3x - 5y = -9 5x - 6y = -8 I believe that I did the first part of this problem correct but can not figure out how to solve for x. Please let me know if

Question 216479: The problem is this:
3x - 5y = -9
5x - 6y = -8
I believe that I did the first part of this problem correct but can not figure out how to solve for x. Please let me know if solving for y is correct and how to solve for x
15x - 25y = -45
15x - 18y = -24 I multiplied the first equation by 5 and the second equation by 3
0 - -7y = -21
I divided both by -7
y = 3
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!

You have correctly solved for the value of

, although I would have multiplied the 2nd equation by -3 and then added the two equations (as opposed to subtracting them like you did). That is because it is less likely to make a sign error if you do it that way.

Now there are two different ways you can determine the value of

.

1. Go back to the original equations and multiply the first one by 6 and the second one by -5. When you add the two equations the

terms will be eliminated and you can solve the result for

2. Select either one of the original equations and substitute the calculated value of

leaving you with an easily solved equation in

. In this problem:

Usually the 2nd method is simpler and less prone to error.

John

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