Line BC is represented by 3x + 2y = 8. Line AD is represented by –3x – 2y = 6. What is the relationship of line BC to line AD? Explain how the sum of the equations demonstrates this relationship.

1 answer

To determine the relationship between line BC (represented by the equation \(3x + 2y = 8\)) and line AD (represented by the equation \(-3x - 2y = 6\)), we can examine both equations.

First, let's rewrite both equations in slope-intercept form \(y = mx + b\), where \(m\) is the slope and \(b\) is the y-intercept.

For line BC:

Starting from the equation: \[ 3x + 2y = 8 \] We can isolate \(y\): \[ 2y = -3x + 8 \] \[ y = -\frac{3}{2}x + 4 \] So, the slope (\(m\)) of line BC is \(-\frac{3}{2}\).

For line AD:

Starting from the equation: \[ -3x - 2y = 6 \] We can isolate \(y\): \[ -2y = 3x + 6 \] Dividing by -2: \[ y = -\frac{3}{2}x - 3 \] So, the slope (\(m\)) of line AD is \(-\frac{3}{2}\).

Relationship between lines:

Since both lines have the same slope of \(-\frac{3}{2}\), they are parallel to each other.

Examining the sum of the equations:

Now let's analyze the sum of the two equations:

  1. Equation of line BC: \(3x + 2y = 8\)
  2. Equation of line AD: \(-3x - 2y = 6\)

Adding both equations: \[ (3x + 2y) + (-3x - 2y) = 8 + 6 \] This simplifies to: \[ 0 = 14 \]

The left side equals zero, which shows that the two lines do not intersect, confirming that they are parallel (since parallel lines do not intersect at any point).

Conclusion:

The relationship between line BC and line AD is that they are parallel lines. The sum of their equations resulting in a false statement (\(0 = 14\)) illustrates that there is no solution simultaneous to both equations, reinforcing the fact that the lines do not intersect.