Can this system of inequalities be solved for x?

Click For Summary

Homework Help Overview

The discussion revolves around solving a system of inequalities represented by the equations x - 2y ≤ 54 and x + y ≥ 93. Participants are exploring whether these inequalities can be solved for x and how to approach the problem algebraically or graphically.

Discussion Character

  • Exploratory, Assumption checking, Mixed

Approaches and Questions Raised

  • Some participants suggest starting with the equalities to find common solutions for x and y. Others question how to represent the inequalities graphically to identify the regions they define. There is also a discussion about whether a single x-value can be determined or if it depends on y.

Discussion Status

The discussion is ongoing, with participants providing various approaches, including graphical and algebraic methods. Some guidance has been offered regarding the graphical representation of the inequalities, but there is no explicit consensus on a single method to solve the problem.

Contextual Notes

Participants note that the inequalities define entire regions rather than specific points, which raises questions about how to interpret the solutions within those regions.

annamal
Messages
393
Reaction score
33
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.
 
Last edited by a moderator:
Physics news on Phys.org
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.
 
  • Like
Likes   Reactions: SammyS

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
Replies
3
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
4
Views
3K
Replies
18
Views
3K
Replies
9
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K