Question

How do graph $x + y = 3$ by plotting points?

Answer 1

Hint : We will solve this question by plotting points. First, we will assume the value of $x = 0$ , by applying the assumed value of $x$ , we will get the coordinate of $y$ . Then, we will assume the value of $y = 0$ , and we will apply it in the equation, by which we will get the $x$ coordinate. Finally, we will plot the points in the graph.

Complete step-by-step answer :
Now, the given equation is $x + y = 3$ .
Let us consider $x = 0$ , by substituting we have,
$0 + y = 3$
$y = 3$
Therefore, the point is $\left( {0,3} \right)$ .
Now, let us consider $y = 0$ , by substituting we have,
$x + 0 = 3$
$x = 3$
Therefore, the point is $\left( {3,0} \right)$
Hence, the points are $\left( {0,3} \right)$ and $\left( {3,0} \right)$ .
Now, let us plot the points graphically,

Note : We can also determine the points using slope-intercept form. The slope-intercept form is probably the most frequently used way to express the equation of a line. Equation of straight line is usually written in the slope-intercept form i.e., $y = mx + b$ , where the $m$ is the slope and $b$ is the $y$ - intercept. When we are given an equation in slope- intercept form, we can use the $y$ - intercept as the point, then out the slope from there. When an equation of a line is not given in slope-intercept form, our first step will be to solve the equation for $y$ . Sometimes the slope intercept form will be called as $y$ -form.