SOLUTION: Write and graph an inequality whose graph is described by the given information. The points (-7,-16) and (1,8) lie on the boundary line. The points (-7,0) and (3,14) are not sol

Algebra ->  Graphs -> SOLUTION: Write and graph an inequality whose graph is described by the given information. The points (-7,-16) and (1,8) lie on the boundary line. The points (-7,0) and (3,14) are not sol      Log On


   

Question 840516: Write and graph an inequality whose graph is described by the given information.
The points (-7,-16) and (1,8) lie on the boundary line. The points (-7,0) and (3,14) are not solutions of the inequality.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
FIND BOUNDARY LINE

y=mx+b
m=%288-%28-16%29%29%2F%281-%28-7%29%29=24%2F8=3
m=3.
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Take either point of the line,
b=y-mx
b=8-3%2A1
b=5
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Boundary Line, highlight_green%28y=3x%2B5%29


EXAMINING NON-SOLUTION POINTS FOR INEQUALITY
Intuition leads me to want Standard Form for this.
-3x%2By=5.
Test the non-solution point to find if it gives left side member greater than or less than 5. Also be sure to find if it is on the boundary or not on the boundary.
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Are (-7,0) and (3,14) on the boundary?
POINT (-7,0):-3%2A%28-7%29%2B0=5
21=5, No.
POINT (3,14): -3%2A3%2B14=5
14-9=5, Yes.
Now we know, because (3,14) is ON the line and NOT a solution, we have a strict inequality. The line does NOT contain points of the inequality solution.
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Look again at the non-solution point (-7,0).
When tested in -3x+y versus 5 what was found was -3x%2By%3E5,
So THAT is the inequality we find.
highlight%28highlight%28-3x%2By%3E5%29%29.
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Unless teacher or book specifies differently, the choice of keeping in standard form or making into slope-intercept form is yours. You could report, y%3E3x%2B5.