SOLUTION: I been working on these problems with my daugther but not very good. Question one. Graph the inequality on a plane 8x-7 less than 15x+y. Second problem Graph the system of inequal

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Question 174581: I been working on these problems with my daugther but not very good. Question one. Graph the inequality on a plane 8x-7 less than 15x+y. Second problem Graph the system of inequalities. y greater than-3 x greater than 4. Third problem Graph the system of inequalities. x+3y less than 9, 3x+y less than 9, x greater than 0, y greater than 0.
Answer by Edwin McCravy(20062) About Me  (Show Source):
You can put this solution on YOUR website!
I been working on these problems with my daugther but not very good. Question one. Graph the inequality on a plane 8x-7 less than 15x+y.

8x-7%3C15x%2By

First draw the graph of the boundary line, which has
the equation formed by replacing the inequality
symbol <  by =. So first graph 8x-7=15x%2By by 
finding two points.  

let, say, x=0, substitute in 8x-7=15x%2By 
8%280%29-7=15%280%29%2By
0-7=0%2By
-7=y
So one point on that line is matrix%281%2C1%2C%22%280%2C-7%29%22%29

Now let, say, y=0, substitute in 8x-7=15x%2By 
8x-7=15x%2B%280%29
-7=7x
-1=x
So another point on that line is matrix%281%2C1%2C%22%28-1%2C0%29%22%29
So we plot those two points, and draw a dotted line through
them:



Now we have to shade one side of that line.  So we choose
any point that is NOT on that line to see if it is or is not
a solution to the original inequality 8x-7%3C15x%2By

Let's arbitrarily pick a test point, say (3,2), and substitute
x=3 and y=2 in 8x-7%3C15x%2By

8x-7%3C15x%2By
8%283%29-7%3C15%283%29%2B%282%29
24-7%3C45%2B2
17%3C47

Since that is true, we have chosen
a point on the side of the line where
ALL the solutions lie, so all the solutions
to the inequality lie on the same side of
the line as (3,2). So we shade that side of
the line.  I can't shade on here, but you
can on your paper:





Second problem  Graph the system of inequalities. 
systemy+%3E+-3%2C+x+%3E+4. 

Draw the graph of y=-3 which is a dotted horizontal line.
Draw the graph of x=4 which is a dotted vertical line.

Since the inequality is y%3E-3, its solution is ABOVE
this horizontal line.

Since the first inequality is y%3E-3, its solution is TO
THE RIGHT OF this horizontal line.

So only shade the area which is ABOVE the horizontal line
and TO THE RIGHT OF the vertical line.



Third problem Graph the system of inequalities. x+3y less than 9, 3x+y less than 9, x greater than 0, y greater than 0.

The last two inequalities are the areas above the x-axis
and to the right of the y-axis. Their boundaries are the
axes themselves.  You'll shade the the part that is below
each of the dotted lines and to the right of the axes:


Edwin