I will show your guys how to plot $xy$ linear equation on Cartesian coordinate system

Let's plot the following equation:
$2x + 3y = 8$

1. First, we need to know $xy$ linear equation is a line
2. A line is determined by two points

Once we have the above two pieces of information, we pretty much know how to solve the problem.

Choose first Point:
Since we know two points determines a line.
We can choose a point.
What point we should choose?
Well, we can choose a very "easy" point.
let $x = 1$, then
$2(1) + 3y = 8$
$\Rightarrow 3y = 6$
$\Rightarrow y = 2$
point: $(x = 1, y = 2)$ is on the line

Choose second point:
How we choose the second point?
Well, We try to choose a "easy" point too.
let $y = 0$
$\Rightarrow 2x + 3(0) = 8$
$\Rightarrow 2x = 8$
$\Rightarrow x = 4$
point: $(x = 4, y = 0)$ is on the line.

Note: when you choose the second point, make sure you choose a different point from the first point.