SOLUTION: In the following system of equations, what does x equal? 10x + 9y = 3 8x + y = 6

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Question 703274: In the following system of equations, what does x equal?
10x + 9y = 3
8x + y = 6

Answer by Stitch(470) About Me  (Show Source):
You can put this solution on YOUR website!
Given: 10X+%2B+9Y+=+3 & 8X+%2B+Y+=+6
I find it easier to set both equations equal to zero first
10X+%2B+9Y+-+3+=+0 and 8X+%2B+Y+-+6+=+0
Then you can solve this problem by elimination. To do so you need to change one of the equations so that by equations have the same coefficient with one of the variables. For instance if we multiply the second equation by 9, then both equations will contain a 9Y.
(8X + Y - 6 = 0) * 9
72X+%2B+9Y+-+54+=+0
Since both equations equal zero, we can set them equal to each other
10X+%2B+9Y+-+3+=+72X+%2B+9Y+-+54
Subtract 9Y from both sides
10X+-+3+=+72X+-+54
Subtract 10X from both sides
-3+=+62X+-+54
Add 54 to both sides
51+=+62X
divide both sides by 62
highlight%280.823+=+X%29 *Note that number was rounded
Then you can solve for Y by substituting 0.823 into one of the equations for X.
8X+%2B+Y+=+6
8%2A%280.823%29+%2B+Y+=+6
6.584+%2B+Y+=+6
Y+=+-0.584