Question 268737
 solve each system of inequalities by graphing 
18.
y > 4
Graph y = 4 as a dashed line.
Shade the half-plane ABOVE the dashed line.
{{{graph(400,300,-10,10,-5,10,y > 4)}}}
-----------------------------------------------
y < |x-1|
Graph y = |x-1| as a dashed line.
Shade the area below the v-shaped graph
{{{graph(400,300,-10,10,-10,10,y < abs(x-1),abs(x-1))}}} 
21. 
yless than or equal to -4/3x
Graph y = (-4/3)x as a solid line.
Shade the half-plane BELOW the line.
{{{graph(400,300,-10,10,-10,10,y < (-4/3)x, (-4/3)x)}}}
--------------------------------------------------------------
ygreater than or equal to -|x|
Graph y = -|x| as an upside-down V.
Shade the area ABOVE the V.
{{{graph(400,300,-10,10,-10,10,y > -abs(x),-abs(x))}}}
============================================================
Cheers,
Stan H.