Question 730169:  Write an equation of the line that passes through (8,-5) and is perpendicular to the graph of the line that passes through points (3,5) and (4,9). 
 Answer by lwsshak3(11628)      (Show Source): 
You can  put this solution on YOUR website! Write an equation of the line that passes through (8,-5) and is perpendicular to the graph of the line that passes through points (3,5) and (4,9). 
*** 
Equation of a line: y=mx+b, m=slope, b=y-intercept 
slope(m)=∆y/∆x=(y1-y2)/(x1-x2) 
For the line that passes through points (3,5) and (4,9). 
m=(9-5)/(4-3)=4/1 
.. 
For the line that passes through (8,-5), perpendicular to the first line 
m=-1/4 (negative reciprocal of slope of first line) 
equation: y=(-1/4)x+b 
solve for b using given coordinates(8,-5) on the line 
-5=(-1/4)*8+b 
-5=-2+b 
b=-3 
equation: y=-x/4-3 
  | 
 
  
 
 |   
 
 |