Which of the following equations has exactly one solution? (1 point)

- 3x + 8 = - 3x - 8

- 3x - 8 = 3x - 8

3x - 8 = 3x + 8

- 8x + 3 = - 8x + 3

1 answer

To determine which equation has exactly one solution, let's solve each equation one at a time.

  1. Equation: \(3x + 8 = -3x - 8\)
    Adding \(3x\) to both sides: \[ 6x + 8 = -8 \] Subtracting 8 from both sides: \[ 6x = -16 \] Dividing by 6: \[ x = -\frac{8}{3} \] This equation has exactly one solution: \(x = -\frac{8}{3}\).

  2. Equation: \(3x - 8 = 3x - 8\)
    If we subtract \(3x\) from both sides: \[ -8 = -8 \] This is a true statement but does not isolate \(x\).
    This equation has infinite solutions.

  3. Equation: \(3x - 8 = 3x + 8\)
    Subtracting \(3x\) from both sides: \[ -8 = 8 \] This is a false statement and represents no solution.
    This equation has no solutions.

  4. Equation: \(8x + 3 = -8x + 3\)
    Adding \(8x\) to both sides: \[ 16x + 3 = 3 \] Subtracting 3 from both sides: \[ 16x = 0 \] Dividing by 16: \[ x = 0 \] This equation has exactly one solution: \(x = 0\).

In conclusion, the equations that have exactly one solution are:

  • \(3x + 8 = -3x - 8\) with the solution \(x = -\frac{8}{3}\)
  • \(8x + 3 = -8x + 3\) with the solution \(x = 0\)

Therefore, the equations having exactly one solution are:

  • 3x + 8 = -3x - 8 and 8x + 3 = -8x + 3.