Consider the line 9x - 7y = -3.What is the slope of a line parallel to this line?What is the slope of a line perpendicular to this line?

Answer :

Given:

[tex]9x-7y=-3[/tex]

The given equation of the line is written in standard form.

We will write the equation in slope-intercept form, we will solve the equation for (y) as follows:

[tex]\begin{gathered} 9x-7y=-3 \\ -7y=-9x-3\rightarrow(\div(-7)) \\ \frac{-7y}{-7}=\frac{-9x}{-7}+\frac{-3}{-7} \\ \\ y=\frac{9}{7}x+\frac{3}{7} \end{gathered}[/tex]

So, the slope of the line = 9/7

We will answer the following questions:

a) What is the slope of a line parallel to this line?

The parallel lines have the same slope

So, the slope of a parallel line = 9/7

b) What is the slope of a line perpendicular to this line?

the product of the slopes of the perpendicular lines = -1

So, we will find the negative of the reciprocal of the given slope

So, the slope of the perpendicular line = -7/9