Can this system of inequalities be solved for x?

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SUMMARY

The discussion focuses on solving the system of inequalities defined by the equations x - 2y ≤ 54 and x + y ≥ 93. Participants emphasize the importance of graphing these inequalities to identify the overlapping regions, which represent the solution set. Algebraic manipulation, such as multiplying the second equation by 2 to yield 2x + 2y ≥ 184, is discussed, but the consensus is that a graphical approach is more effective for visualizing the solution space. The key takeaway is that the solution consists of all (x, y) points within the overlapping regions of the defined half-planes.

PREREQUISITES
  • Understanding of linear inequalities
  • Ability to graph equations in the xy-plane
  • Familiarity with algebraic manipulation of inequalities
  • Knowledge of half-planes and their geometric representation
NEXT STEPS
  • Learn how to graph linear inequalities in the xy-plane
  • Study the concept of half-planes and their intersections
  • Explore algebraic methods for solving systems of inequalities
  • Investigate the use of software tools like GeoGebra for visualizing inequalities
USEFUL FOR

Students and educators in precalculus, mathematicians interested in systems of inequalities, and anyone seeking to enhance their understanding of graphical solutions in algebra.

annamal
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Summary: Can these two equations be solved for x like a system of linear inequalities, and how?
##x- 2y \le 54##
##x + y \ge 93##

We start with
##x- 2y \le 54##
##x + y \ge 93##

Multiplying the second equation by 2, we have ##2x + 2y \ge 184##. We cannot seem to cancel the y out with the first equation because that would create an unclear inequality. So how do we solve it algebraically?

MENTOR NOTE: Moved to Precalculus Homework Help hence no template.
 
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Draw the individual inequalities as straight lines in the xy-plane.
How can you use this to figure out when both your inequalities are satisfied?
Is there a single x-value, or does it depend on y?
 
malawi_glenn said:
Draw the individual inequalities as straight lines in the xy-plane.
How can you use this to figure out when both your inequalities are satisfied?
Is there a single x-value, or does it depend on y?
That is solving it graphically. I would like to solve it algebraically.
 
Start with the equalities first to find a common x,y that solves them.

BEFORE WE GO ANY FURTHER: PLEASE SHOW SOME WORK.
 
The graphical solution will just be an aid for your algebra
 
annamal said:
Summary: Can these two equations be solved for x like a system of linear inequalities, and how?
##x- 2y \le 54##
##x + y \ge 93##
You don't want to "solve" for x and y. Because these inequalities define two entire regions (half planes), not two thin lines with one intersection point.
y=13 and x=80 is the solution of x-2y=54; x+y=23. That doesn't tell you much.
Instead, you want to graph the lines x-2y=54; x+y=23 to see what the two regions (half planes) of the two inequalities are. Then you can see where the regions overlap. All the (x,y) points in the overlap are the answer.
 
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