SOLUTION: Graph each of the following inequalities 2. 4x + 3y > 12

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Question 124402: Graph each of the following inequalities


2. 4x + 3y > 12

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
In order to graph 4x%2B3y%3E12, we need to graph the equation 4x%2B3y=12 (just replace the inequality sign with an equal sign).
So lets graph the line 4x%2B3y=12 (note: if you need help with graphing, check out this solver)
+graph%28+500%2C+500%2C+-20%2C+20%2C+-20%2C+20%2C+-%284%2F3%29x%2B4%29+ graph of 4x%2B3y=12
Now lets pick a test point, say (0,0). Any point will work, (just make sure the point doesn't lie on the line) but this point is the easiest to work with. Now evaluate the inequality 4x%2B3y%3E12 with the test point

Substitute (0,0) into the inequality
4%280%29%2B3%280%29%3E12 Plug in x=0 and y=0
0%3E12 Simplify



(note: for some reason, some of the following images do not display correctly in Internet Explorer. So I recommend the use of
Firefox to see these images.)


Since this inequality is not true, we do not shade the entire region that contains (0,0). So this means we shade the region that is on the opposite side of the line
Graph of 4x%2B3y%3E12 with the boundary (which is the line 4x%2B3y=12 in red) and the shaded region (in green)
(note: since the inequality contains a greater-than sign, this means the boundary is excluded. This means the solid red line is really a dashed line)