a system of linear equations y= 2x+5 and y=x+2 which ordered pair is a solution to the equations?

a. (-3, -1)
b. (2, 9)
c. (3, 1)
d. (4, 6)

1 answer

To determine which ordered pair is a solution to the system of linear equations given by \(y = 2x + 5\) and \(y = x + 2\), we need to check each ordered pair and see if both equations are satisfied.

  1. For \( (-3, -1) \):

    • Substitute \(x = -3\) into \(y = 2x + 5\): \[ y = 2(-3) + 5 = -6 + 5 = -1 \quad \text{(True)} \]
    • Substitute \(x = -3\) into \(y = x + 2\): \[ y = -3 + 2 = -1 \quad \text{(True)} \]
    • Both equations are satisfied.
  2. For \( (2, 9) \):

    • Substitute \(x = 2\) into \(y = 2x + 5\): \[ y = 2(2) + 5 = 4 + 5 = 9 \quad \text{(True)} \]
    • Substitute \(x = 2\) into \(y = x + 2\): \[ y = 2 + 2 = 4 \quad \text{(False)} \]
    • Only the first equation is satisfied.
  3. For \( (3, 1) \):

    • Substitute \(x = 3\) into \(y = 2x + 5\): \[ y = 2(3) + 5 = 6 + 5 = 11 \quad \text{(False)} \]
    • No need to check the second equation since the first is already false.
  4. For \( (4, 6) \):

    • Substitute \(x = 4\) into \(y = 2x + 5\): \[ y = 2(4) + 5 = 8 + 5 = 13 \quad \text{(False)} \]
    • No need to check the second equation since the first is already false.

Therefore, the only ordered pair that is a solution to both equations is:

a. (-3, -1).