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Solve the system of equations - 4x + 2y = -30 and – 2x + 2y = -10 by
combining the equations.

User Selin
by
5.2k points

1 Answer

4 votes

Answer:

(x, y) = (10, 5)

Explanation:

We notice that the y-coefficient is the same in both equations, and that the x-coefficient is smaller in the first equation. Subtracting one equation from the other will eliminate the y-variable. Subtracting the first equation from the second will result in a positive coefficient for x.

Subtracting the first equation from the second, we have ...

(-2x +2y) -(-4x +2y) = (-10) -(-30)

2x = 20 . . . .simplify

x = 10 . . . . . divide by 2

Substituting for x in the second equation gives ...

-2(10) +2y = -10

2y = 10 . . . . add 20

y = 5 . . . . . . divide by 2

The solution is (x, y) = (10, 5).

User Jayprakash Dubey
by
5.0k points