Question 319062:  Are the pair of lines parallel, perpendicular, or neither? 
5x+3y=4 
3x-5y=9 
 Found 2 solutions by  solver91311, CharlesG2: Answer by solver91311(24713)      (Show Source):  Answer by CharlesG2(834)      (Show Source): 
You can  put this solution on YOUR website! Are the pair of lines parallel, perpendicular, or neither? 
5x+3y=4 
3x-5y=9
 
if lines parallel --> slopes equal 
if lines perpendicular --> slopes are negative reciprocals 
(for example if one slope is 1/3 the other slope would be -3) 
converting to slope-intercept form of y=mx+b, where m is the slope, and b is the y-intercept (vertical-intercept or the point (0,b) 
first line: 
5x + 3y = 4 
3y = -5x + 4 
y = (-5/3)x + 4/3 
second line: 
3x - 5y = 9 
-5y = -3x + 9 
y = (3/5)x - 9/5 
slopes are -5/3 on one, and 3/5 on the other, the lines are perpendicular 
 
  | 
 
  
 
 |   
 
 |