Give the geometric representations of 2x + 9 = 0 as an equation <br/><br/> (i) in one variable <br/><br/>(i) in two variables

Solution:

(i) In one variable, $2 x+9=0$ represents a point $x=\frac{-9}{2}=-4.5$ as shown in the following figure.



(ii) In two variables, $2 x+9=0$ represents a straight line passing through point $(-4.5,0)$ and parallel to $y$-axis. It is a collection of all points of the plane, having their $x$-coordinate as $4.5$.