Question

Give the geometric representations of $2x+9=0$ as an equation
(i) in one variable
(ii) in two variable

Answer 1

(i) In one variable

Given equation is $2x+9=0$

$\Rightarrow 2x=-9$

$\Rightarrow x=\frac{-9}{2}=-4.5$

Point B $(-4.5,0)$ is representing $2x+9=0$

(ii) Given equation is $2x+9=0$

$\Rightarrow 2x+0y+9=0$

$\Rightarrow 0y=-2x-9$

$\begin{array}{ccc}x& -4.5& -4.5\\ y& 0& 2\end{array}$

It is line parallel to $y$-axis at a negative distance $(-4.5)$

Two points lying it are the points $A(-4.5,0),B(-4.5,2).$

In one variable $x$ just represent a point $B(-4.5,0)$ whereas in two variable it represents a line $(2x+9=0)$