SOLUTION: Solve, using linear combination. 3x + y = 4 2x + y = 5

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Question 829473: Solve, using linear combination.
3x + y = 4
2x + y = 5
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.3x+%2B+y+=+4
2.2x+%2B+y+=+5
Subtract eq. 2 from eq. 1 (or form a linear combination of eq. 1 and (-1)*eq. 2),
3x%2By-2x-y=4-5
highlight%28x=-1%29
Then use either equation to solve for y.
3%28-1%29%2By=4
-3%2By=4
highlight%28y=7%29