What is the equation of the line that passes through (1,2) and is parallel to the line whose equation is 4x+y-1=0?

1 Answer
Jun 25, 2016

y=-4x+6

Explanation:

Look at the diagram

The given line (Red Colour Line) is -

4x+y-1=0
The required line (Green Colour Line) is passing through the point (1,2)

Step - 1

Find the slope of the given line.

It is in the form

ax+by+c=0
Its slope is defined as
m_1=(-a)/b=(-4)/1=-4

Step -2

The two lines are parallel.
Hence, their slopes are equal
The slope of the required line is

m_2=m_1=-4

Step - 3

The equation of the required line

y=mx+c

Where-

m=-4
x=1
y=2

Find c

c+mx=y
c+(-4)1=2
c-4=2
c=2+4=6

After knowing c

use the slope -4 and intercept 6 to find the equation

y=-4x+6
Parallel LinesParallel Lines