How do you graph 2(y-1) > 3(x+1)2(y1)>3(x+1)?

1 Answer
Apr 3, 2015

First of all, let's manipulate the expression to isolate the yy term:

  • 2(y-1)=2y-22(y1)=2y2
  • 3(x+1)=3x+33(x+1)=3x+3.
    So, the expression is equivalent to 2y-2>3x+32y2>3x+3
    Add 22 to both sides:
    2y>3x+52y>3x+5
    Divide by 22 both sides:
    y>3/2 x + 5/2y>32x+52

Now, it's easy to plot the equation y=3/2 x+ 5/2y=32x+52, since it is a line. That line is the graph of the equation, which means the set of points
which realize y=3/2 x + 5/2y=32x+52, and you want the set of points composed of all the greater yy's. This simply means that you must consider the area above the line to solve the equation, as you can see in the graph:

graph{y>3/2 x + 5/2 [-10, 10, -5, 5]}

Note that the line itself is not part of the solution, because you have the strict inequality and so the set of points y=3/2 x + 5/2y=32x+52 is not to be considered