SOLUTION: if the graph of the equation ax + 3y =9 is perpendiculer to 3x + y =-4 whats the value of a

Algebra ->  Linear-equations -> SOLUTION: if the graph of the equation ax + 3y =9 is perpendiculer to 3x + y =-4 whats the value of a      Log On


   

Question 349605: if the graph of the equation ax + 3y =9 is perpendiculer to 3x + y =-4 whats the value of a
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find the slope of each line by convert to slope-intercept form, y=mx%2Bb.
ax%2B3y=9
3y=-ax%2B9
y=-%28a%2F3%29x%2B3
m1=-%28a%2F3%29
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3x%2By=-4
y=3x-4
m2=3
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Perpendicular lines have slopes that are negative reciprocals,
m1%2Am2=-1
-%28a%2F3%29%2A3=-1
highlight%28a=1%29
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graph%28300%2C300%2C-10%2C10%2C-10%2C10%2C-%281%2F3%29x%2B3%2C3x-4%29