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What is the solution to this system of equations?



2x + y = 40

x − 2y = −20

1 Answer

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Final answer:

The solution to the system of linear equations is found using the elimination method, resulting in the solution (x, y) = (12, 16).

Step-by-step explanation:

The solution to the system of equations:

  • 2x + y = 40
  • x - 2y = -20

can be found using the method of substitution or elimination. For example, using the elimination method:

  1. Multiply the second equation by 2 to align terms with the first equation:
    2(x - 2y) = 2(-20)
    2x - 4y = -40
  2. Add this result to the first equation to eliminate x:
    2x + y + 2x - 4y = 40 - 40
    4x - 3y = 0
  3. Solve for y:
    3y = 4x
    y = 4/3x
  4. Substitute y = 4/3x back into the first equation:
    2x + 4/3x = 40
    10/3x = 40
    x = 12
  5. Substitute x = 12 into y = 4/3x:
    y = 4/3(12)
    y = 16

The solution to the system is (x, y) = (12, 16).

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