Answer:
(x, y) = (5, 7)
Step-by-step explanation:
It can be useful to put these equations into standard form, with mutually-prime coefficients and a positive x-coefficient.
10x +y -(4x +4y) = 9 . . . . . subtract the variable terms on the right
6x -3y = 9 . . . simplify
2x -y = 3 . . . . . divide by 3 to put in standard form
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(x +10y) -(10x +y) = 18 . . . . . subtract the variable terms on the right
-9x +9y = 18 . . . simplify
x -y = -2 . . . . . . . divide by -9 to put in standard form
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Now, we can subtract the second equation from the first.
(2x -y) -(x -y) = 3 -(-2)
x = 5
y = x+2 = 7 . . . from the second simplified equation
The solution is (x, y) = (5, 7).
