SOLUTION: Find the slope and y-intercept of the line that is perpendicular to y=3x−4 and passes through the point (6,−7) .

Algebra ->  Linear-equations -> SOLUTION: Find the slope and y-intercept of the line that is perpendicular to y=3x−4 and passes through the point (6,−7) .      Log On


   

Question 688021: Find the slope and y-intercept of the line that is perpendicular to y=3x−4 and passes through the point (6,−7) .
Found 2 solutions by josmiceli, lwsshak3:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The slope of the line +y+=+3x+-+4+ is +3+
The slope of any line which is perpendicular to
this line is +m%5B2%5D+=+-1%2Fm%5B1%5D+
+m%5B2%5D+=+-1%2F3+
You can use the general point-slope formula
+%28+y+-%28-7%29+%29+%2F+%28+x+-+6+%29+=+-1%2F3+
+%28+y+%2B+7+%29+%2F+%28+x+-+6+%29+=+-1%2F3+
+3%2A%28+y+%2B+7+%29+=+-%28+x+-+6+%29+
+3y+%2B+21+=+-x+%2B+6+
+3y+=+-x+-+15+
+y+=+%28+-1%2F3+%29%2Ax+-+5+
The slope is -1/3
The y-intercept is -5
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here's a plot of the 2 lines:
+graph%28+400%2C+400%2C+-6%2C+6%2C+-7%2C+4%2C+3x+-+4%2C+%28-1%2F3%29%2Ax+-+5+%29+

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Find the slope and y-intercept of the line that is perpendicular to y=3x−4 and passes through the point (6,−7)
**
equation of a line: y=mx+b, m=slope, b=y-intercept
slope of given line=3
slope of perpendicular line=-1/3 (negative reciprocal)
equation:
y=-x/3+b
solve for b using coordinates of given point (6,-7)
-7=-6/3+b
-7=-2+b
b=-5
Equation of perpendicular line:
y=-x/3-5
slope of perpendicular line= -1/3
y-intercept of perpendicular line=-5