Question 2 of 10

Which is not an equation of the line going through (6, 7) and (2, -1)?
• A. y -7 = 2(x- 6)
• B. y - 1 = 2(x+ 2)
• c. y= 2x - 5
• D. y+ 1 = 2(x - 2)

1 answer

To determine which option is not an equation of the line passing through the points (6, 7) and (2, -1), we first need to find the slope of the line and then derive the equation of the line.

  1. Calculate the slope \( m \) using the two points (6, 7) and (2, -1):

\[ m = \frac{y_2 - y_1}{x_2 - x_1} = \frac{-1 - 7}{2 - 6} = \frac{-8}{-4} = 2 \]

  1. Use point-slope form to write the equation of the line. We can use point (6, 7):

\[ y - y_1 = m(x - x_1) \] \[ y - 7 = 2(x - 6) \]

  1. Expanding this gives us the equation:

\[ y - 7 = 2x - 12 \] \[ y = 2x - 5 \quad \text{(this is an equivalent equation)} \]

Now, let's evaluate the options:

  • A. \( y - 7 = 2(x - 6) \) → This is correct.
  • B. \( y - 1 = 2(x + 2) \) → This simplifies to \( y - 1 = 2x + 4 \) or \( y = 2x + 5 \), which is not correct (it does not pass through the points).
  • C. \( y = 2x - 5 \) → This is correct.
  • D. \( y + 1 = 2(x - 2) \) → This simplifies to \( y + 1 = 2x - 4 \) or \( y = 2x - 5 \), which is correct.

From this analysis, the answer is:

B. y - 1 = 2(x + 2) is not an equation of the line.