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Use linear combination

4x-9y=1
-2x+3y=-1

1 Answer

3 votes

Answer:

(x, y) = (1, 1/3)

Explanation:

The x-coefficient in the first equation is -2 times that in the second equation, so adding twice the second equation to the first will eliminate x:

(4x -9y) +2(-2x +3y) = (1) +2(-1)

-3y = -1 . . . . simplify

y = 1/3 . . . . . divide by -3

The y-coefficient in the first equation is -3 times the y-coefficient in the second equation, so adding 3 times the second equation to the first will eliminate y:

(4x -9y) +3(-2x +3y) = (1) +3(-1)

-2x = -2 . . . . . . simplify

x = 1 . . . . . . . . . divide by -3

The solution is (x, y) = (1, 1/3).

User Mookayama
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