What is the equation of the line that goes through (7, 4) and (5, −4)?

y=
4
1

x−20

y=4x−20

y=
4
1

x−24

y=4x−24

1 answer

To find the equation of the line that passes through the points \((7, 4)\) and \((5, -4)\), we can use the two-point form of the equation of a line.

  1. Calculate the slope (m) using the formula: \[ m = \frac{y_2 - y_1}{x_2 - x_1} \] Here, we can take \((x_1, y_1) = (7, 4)\) and \((x_2, y_2) = (5, -4)\): \[ m = \frac{-4 - 4}{5 - 7} = \frac{-8}{-2} = 4 \]

  2. Use the point-slope form of the equation of a line: \[ y - y_1 = m(x - x_1) \] Plugging in one of the points, say \((7, 4)\): \[ y - 4 = 4(x - 7) \]

  3. Expand and simplify: \[ y - 4 = 4x - 28 \] \[ y = 4x - 28 + 4 \] \[ y = 4x - 24 \]

So the equation of the line that passes through the points \((7, 4)\) and \((5, -4)\) is:

\[ y = 4x - 24 \]

Therefore, the correct answer is:

y = 4x - 24.