Find an equation for the line that passes through the point
Solution
Solution:
Equation of line which passed through
(2,-5)
Let the general equation of line
y=mx + c
where m is slope and c is intercept on y axis
(a) given that m = -3
y = -3 x +c
to calculate c
line passes through the point (3,-2 )
plug x = 3 and y =-2
-2 = -3*3 +c
c = 7
therefore
equation of line
y = -3x + 7
(b) if line is parallel to x axis then
then slope would be 0
ie m = 0
y =mx + c = 0x + c
y = c
Plug (-2,5)
c = 5
therefore equation of the line
y = 5
(c) line is parallel to y axis
therefore slope would be infinite
y = mx + c
that means line parallel to y axis
if it pass through
x = 3
thus equation of line is x =3
(d)
If line parallel to
2x -4y = 3
4y = 2x-3
y = (1/2)x -3/4
if two lines are parallel to each other then slope are equal
m = 1/2
therefore
y = mx+c
y=(1/2)x + c
plug (3,-2) to get intercept c
-2 = (1/2)(3) + c
c= 2-3/2
c = 1/2
thus required equation of line is
y = (1/2)x + 1/2
Answer

