SOLUTION: What is the equation of a line that is perpendicular to the line y = 3x + 9 and containing the point (6, –4)? and What is the equation of a line that is parallel to the line

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Question 366438: What is the equation of a line that is perpendicular to the line y = 3x + 9 and containing the point (6, –4)?
and
What is the equation of a line that is parallel to the line y=1/2x+7 equation and containing the point (–4, 7)?

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
What is the equation of a line that is perpendicular to the line y = 3x + 9 and containing the point (6, –4)?
..
y=3x+9
slope = 3
slope of line perpendicular to this line will be negative reciprocal
= -1/3
Point(6,-4)
equation of line passing through point (x1,y1)
=(y-y1)=m(x-x1)
=(y-(-4)=-1/3(x-6)
=y+4 = -x/3+2
y=-1/3*x -4+2
y= -1/3 *x -2
...
The graph will be as below
graph%28300%2C300%2C-5%2C5%2C-5%2C5%2C%283x%2B9%29%2C%28%28-x%2F3%29-2%29%29
and
What is the equation of a line that is parallel to the line y=1/2x+7 equation and containing the point (–4, 7)?
..
y= 1/2 x +7
slope = 1/2
since line required is parallel slope will be same = 1/2
Point ( -4,7)
..
y-y1=m(x-x1)
y-7=1/2(x+4)
y-7= x/2 +2
y=x/2 +9
...
graph%28300%2C300%2C-10%2C2%2C-2%2C10%2C%28%28x%2F2%29%2B7%29%2C%28%28x%2F2%29%2B9%29%29