Given:
The coordinates of the points are B(-4,3), G(-2, 4), H(1, -2), L(-1, -3).
To find:
Whether GL and BH are parallel or not by using their slopes.
Solution:
If a line passes through the two points, then the slope of the line is
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
Using the slope formula, the slope of GL is
[tex]m_1=\dfrac{-3-4}{-1-(-2)}[/tex]
[tex]m_1=\dfrac{-7}{-1+2}[/tex]
[tex]m_1=\dfrac{-7}{1}[/tex]
[tex]m_1=-7[/tex]
Using the slope formula, the slope of BH is
[tex]m_2=\dfrac{-2-3}{1-(-4)}[/tex]
[tex]m_2=\dfrac{-5}{1+4}[/tex]
[tex]m_2=\dfrac{-5}{5}[/tex]
[tex]m_2=-1[/tex]
We know that slopes of parallel lines are always equal.
The slopes of GL and BH are -7 and -1 respectively but they are not equal, therefore GL and BH are not parallel lines.