SOLUTION: consider the line y= -9x+7 Find the equation of the line that is parallel to this line and passes through the point (-3,-5) Find the equation of the line that is perpendicular

Algebra ->  Linear-equations -> SOLUTION: consider the line y= -9x+7 Find the equation of the line that is parallel to this line and passes through the point (-3,-5) Find the equation of the line that is perpendicular      Log On


   



Question 592978: consider the line y= -9x+7
Find the equation of the line that is parallel to this line and passes through the point (-3,-5)
Find the equation of the line that is perpendicular to this line and passes
through the point (-3,-5)

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
PARALLEL



y = -9 x + 7
Divide by 1
y = -9 x + 7
Compare this equation with y=mx+b
slope m = -9
The slope of a line parallel to the above line will be the same
The slope of the required line will be -9
m= -9 ,point ( -3 , -5 )
Find b by plugging the values of m & the point in
y=mx+b
-5=27+b
b= -32
m= -9
Plug value of the slope and b in y = mx +b
The required equation isy=-9x-32
PERPENDICULAR TO A LINE
y = -9 x + 7
Divide by 1
y = -9 x + 7
Compare this equation with y=mx+b, m= slope & b= y intercept
slope m = -9

The slope of a line perpendicular to the above line will be the negative reciprocal 1/9
m1*m2=-1
The slope of the required line will be 1/9

m= 1/9 ,point ( -3 , -5 )
Find b by plugging the values of m & the point in
y=mx+b
-5 = - 1/ 3 + b
b= -14/3
m= 1/9
The required equation is y = 1/ 9x-14/ 3
m.ananth@hotmail.ca