# How do you graph x+y=8 using intercepts?

Jan 15, 2017

#### Explanation:

There are two ways of doing it.

One $\to$ The intercept form of the equation is $\frac{x}{a} + \frac{y}{b} = 1$, where $a$ and $b$ are the intercepts formed by the line on $x$-axis and $y$-axis.

As the equation is $x + y = 8$, dividing each term by $8$, we get

$\frac{x}{8} + \frac{y}{8} = 1$

and hence, intercepts formed by the line on $x$-axis is $8$ and on $y$-axis too it is $8$. Hence mark the intercepts $8$ on each axis and join them to draw the graph of $x + y = 8$.

Two $\to$ Just put $x = 0$ to get $y$-intercept, it comes out as $8$, and put $y = 0$ to get $x$-intercept, which too comes out as $8$.

Now as above mark the two intercepts and join to form line.
graph{((x-8)^2+y^2-0.025)((y-8)^2+x^2-0.025)(x+y-8)=0 [-7.79, 12.21, -1.32, 8.68]}