Equation of a Line with X-Intercept
Consider the straight line and let
be the inclination of the straight line as shown in the given diagram. Now the slope of the line is represented by
. Let
be any point on the given line
. Let
be the X-intercept of the straight line, so the line must pass through the point
.
Take as the X-intercept of the straight line so the line must pass through the point
, i.e.
X-intercept. From point
draw
perpendicular to the
-axis.

Now from the given diagram, consider the triangle , i.e.
, and by the definition of slope we take
Now by the definition we can use instead of
, and we get
This is the equation of a straight line having the slope and X-intercept
.
NOTE: It may be noted that if the line passes through the origin , then the X-intercept is equal to zero, i.e.
, so the equation of the straight line becomes
.
Example: Find the equation of a straight line having the slope and X-intercept equal to
.
Here we have slope and X-intercept
Now using the formula of a straight line having a slope and X-intercept
Substitute the above values in the formula to get the equation of a straight line
This is the required equation of straight line.