# How do you graph the line x+4y=4?

Jun 22, 2016

Select at least two sets of coordinates that satisfy the given equation;
plot these points;
draw a line through the points.

#### Explanation:

Given the equation $x + 4 y = 4$

Its is probably easiest to find values of $x$ for a few simple values of $y$

{: (underline(y),rarr,underline(x)), (0,rarr,4), (1,rarr,0), (2,rarr,-4) :}
so we have coordinate points:
$\textcolor{w h i t e}{\text{XXX}} \left(x , y\right) \in \left\{\begin{matrix}4 & 0 \\ 0 & 1 \\ - 4 & 2\end{matrix}\right\}$

Plotting these coordinates and drawing a line through them:
graph{((x-4)^2+y^2-0.02)(x^2+(y-1)^2-0.02)((x+4)^2+(y-2)^2-0.02)(x+4y-4)=0 [-7.023, 7.024, -3.51, 3.513]}

Note that two coordinates would have been sufficient but use of at least three helps ensure no accidental errors.