Jessica 🤍 is making a map for school and coordinate plane. To hallways in the school perpendicular to each other. The main hallway passes through the points (-five, nine) and (four, six) the perpendicular hallway passes through the point (-4, three) equations for the lines that represent main hallway and the perpendicular hallway

1 answer

To find the equations of the main hallway and the perpendicular hallway, we can follow these steps:

Step 1: Find the equation of the main hallway

Given points on the main hallway:
Point A \((-5, 9)\)
Point B \((4, 6)\)

Step 1.1: Calculate the slope of the main hallway.

The slope \(m\) is given by the formula: \[ m = \frac{y_2 - y_1}{x_2 - x_1} \]

Substituting in the coordinates of points A and B: \[ m = \frac{6 - 9}{4 - (-5)} = \frac{-3}{4 + 5} = \frac{-3}{9} = -\frac{1}{3} \]

Step 1.2: Find the equation of the line using point-slope form.

The point-slope form of a line is: \[ y - y_1 = m(x - x_1) \] Using point A \((-5, 9)\): \[ y - 9 = -\frac{1}{3}(x - (-5)) \] \[ y - 9 = -\frac{1}{3}(x + 5) \] Distributing the slope: \[ y - 9 = -\frac{1}{3}x - \frac{5}{3} \] Adding 9 to both sides to isolate y: \[ y = -\frac{1}{3}x - \frac{5}{3} + 9 \] Converting 9 to a fraction: \[ 9 = \frac{27}{3} \] So we have: \[ y = -\frac{1}{3}x + \frac{27 - 5}{3} \] \[ y = -\frac{1}{3}x + \frac{22}{3} \]

Equation of the main hallway: \[ y = -\frac{1}{3}x + \frac{22}{3} \]

Step 2: Find the equation of the perpendicular hallway

Given point on the perpendicular hallway:
Point C \((-4, 3)\)

Step 2.1: Calculate the slope of the perpendicular hallway.

The slope of a line perpendicular to another is the negative reciprocal of the original slope. Since the slope of the main hallway is \(-\frac{1}{3}\), the slope of the perpendicular hallway \(m_{\perpendicular}\) is: \[ m_{\perpendicular} = -\frac{1}{-\frac{1}{3}} = 3 \]

Step 2.2: Find the equation of the perpendicular line using point-slope form.

Using point C \((-4, 3)\): \[ y - 3 = 3(x - (-4)) \] \[ y - 3 = 3(x + 4) \] Distributing the slope: \[ y - 3 = 3x + 12 \] Adding 3 to both sides: \[ y = 3x + 15 \]

Equation of the perpendicular hallway: \[ y = 3x + 15 \]

Summary of equations:

  • Main hallway: \(y = -\frac{1}{3}x + \frac{22}{3}\)
  • Perpendicular hallway: \(y = 3x + 15\)