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4 votes
5x - 9y=1
-7x + 2y = -5​

User Sparker
by
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1 Answer

5 votes

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Answer:

(x, y) = (43/53, 18/53)

Explanation:

If we want to eliminate the x-terms, we multiply the first equation by 7 (opposite of the x-coefficient in the second equation), and we multiply the second equation by 5 (x-coefficient in the first equation). Then we add the result.

7(5x -9y) +5(-7x +2y) = 7(1) +5(-5)

35x -63y -35x +10y = 7 -25

-53y = -18 . . . . simplify. Note the x-terms are gone.

y = 18/53 . . . . . divide by -53

__

Putting this value of y in the first equation, we get ...

5x -9(18/53) = 1

5x = 1 + 162/53 = 215/53 . . . . . add 9y to both sides, simplify

x = 43/53 . . . . . . . . . . divide by 5

The solution is (x, y) = (43/53, 18/53).

User Lihongxu
by
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