Given:
The equation of a line is:
[tex]y-1=4x[/tex]
A line parallel to the above line passes through the point P(2,5).
To find:
The equation of the parallel line.
Solution:
The slope intercept form of a line is:
[tex]y=mx+b[/tex] ...(i)
Where, m is the slope and b is the y-intercept.
The given equation is:
[tex]y-1=4x[/tex]
It can be rewritten as
[tex]y=4x+1[/tex] ...(ii)
On comparing (i) and (ii), we get
[tex]m=4[/tex]
It means the slope of the given line is 4.
We know that the slopes of two perpendicular lines are equal. So, the slope of the required parallel line is also 4.
The parallel line passes through the point P(2,5) with slope 4, thus the equation of the parallel line is
[tex]y-y_1=m(x-x_1)[/tex]
[tex]y-5=4(x-2)[/tex]
[tex]y-5=4x-8[/tex]
[tex]y=4x-8+5[/tex]
[tex]y=4x-3[/tex]
Therefore, the equation of the required parallel line is [tex]y=4x-3[/tex].
