Question 544675
In order plot a graph, we want the equation in the slope/intercept form, y = mx + b
:
2x + 5y = 12
5y = -2x + 12
divide both sides by 5
y = {{{-2/5}}}x + {{{12/5}}}
this will work OK using decimals
y = -.4x + 2.4
:
Choose a couple values for x and find y: 
x = -3
y = -.4(-3) + 2.4
y = +1.2 + 2.4
y = 3.6
:
x = +3
y = -.4(3) + 2.4
y = -1.2 + 2.4
y = + 1.2
:
 x | y
--------
-3 | 3.6
+3 | 1.2
Should look like this
{{{ graph( 300, 200, -5, 8, -5, 5, -.4x+2.4) }}}