Question 366564
{{{3x+4y<=12}}}
{{{4y<=-3x+12}}}
{{{y<=-(3/4)x+3}}}
First graph the line {{{y=-(3/4)x+3}}}
.
.
.
{{{graph(300,300,-5,5,-5,5,0,-(3/4)x+3)}}}
.
.
.
Now choose a point not on the line. 
({{{0}}},{{{0}}}) is a convenient choice.
Test the inequality.
If the inequality is satisfied, shade the region containing ({{{0}}},{{{0}}}).
If not, shade the region that does not contain ({{{0}}},{{{0}}}).
{{{3x+4y<=12}}}
{{{3(0)+4(0)<=12}}}
{{{0<=12}}}
True, shade the region containing ({{{0}}},{{{0}}})
.
.
.

*[invoke plot_any_inequality "3x+4y<=12", -10, 10, -10, 10, 300, 300]