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Patricia wants to solve the system using linear combination by eliminating the y first. Given the equations: equation 1: 2x - 9y = -8 and equation 2: 5x + y = -20. What is the solution to the system of equations?

1) (x, y) = (4, -12)
2) (x, y) = (-4, 12)
3) (x, y) = (4, 12)
4) (x, y) = (-4, -12)

User Azelcer
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1 Answer

4 votes

Final answer:

The system of equations is solved by eliminating variable y, giving us x = -4. Upon substituting x in the second equation, we find y = 0. Therefore, the solution is (x, y) = (-4, 0), which is not presented in the given options.

Step-by-step explanation:

To solve the system of equations using linear combination and eliminate the variable y, we need to manipulate the equations so that when they are added, the y terms cancel out. The equations given are:

  • Equation 1: 2x - 9y = -8
  • Equation 2: 5x + y = -20

To eliminate y, we can multiply Equation 2 by 9 to make the coefficient of y in both equations the same with opposite signs.

  • Modified Equation 2: 45x + 9y = -180

Now, add Equation 1 and the Modified Equation 2:

2x - 9y + 45x + 9y = -8 + (-180)

Combining like terms, we get: 47x = -188

Divide both sides by 47 to find the value of x: x = -4

Now, plug x = -4 back into Equation 2 to find y: 5(-4) + y = -20 -20 + y = -20

Add 20 to both sides: y = 0

Therefore, the solution to the system of equations is (x, y) = (-4, 0), which is not listed in the given options. It looks like the options provided do not match the correct solution for this particular system of equations.

User Ronita
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