Finite Mathematics and Calculus with Applications
(7th Edition)
by Lial, Greenwell, and Ritchey
Section 1.1- Slopes and Equations of Lines
19.
Find the equation of the line through the points   and  
Express the answer in slope-intercept form if possible.
The slope of the line is




  




The equation of the line must be        To find b we can

use the point   Substitute    and    and solve for b.


               




Therefore the equation of the line is     



31.
Find the equation of the line through    perpendicular to
  
Find the slope of the line      by solving for 
       this line has slope  
If 2 lines are perpendicular then their slopes are negative reciprocals.
Therefore, a line perpendicular to      has slope 1 and must be
     Using the point    we see that
               
Therefore the equation of the perpendicular line through    is
  
35.
Do the points    , and      lie on the same line?
If these points lie on the same line, then the slopes of the lines
connecting these points must be equal.



The slope between   and   is

 



The slope between   and      
   
 




 
   
 


These slopes are not equal, so the points do not line on the same line.
59.
Graph the equation      
To make this graph, get at least 2 points on the graph.
Just to make sure I don't make a mistake, I'll get 3 points.
We know the graph is a straight line.
If    then             lies on the line.
If    then             lies on the line.
If     then                  
      lies on the line.
The graph is shown below.