Question 550011
To graph a linear function, like {{{3x+4y=8}}}, all you need to do is determine 2 points, plot them and connect them with a straight line. Choose easy to calculate and plot points that are not too close together. {{{x=0}}} and/or {{{y=0}}} are often useful.
For {{{x=0}}}, {{{3x+4y=3*0+4y=0+4y=4y=8}}} ---> {{{y=2}}}, giving us the point (0,2).
For {{{x=4}}}, {{{3x+4y=3*4+4y=12+4y=8}}} ---> {{{4y=8-12=-42}}} ---> {{{y=-1}}}, giving us the point (4,-1).
{{{drawing (300,300,-2,6,-2,6,
grid(1),
blue(circle (0,2,0.2)), locate(0,2.5,"(0,2)"),
blue(circle(4,-1,0.2)), locate(3.9,-0.5,"(4,-1)"),
blue(line(-2,7/2, 8,-4))
)}}}