How to Solve Rational Inequalities?

In summary, the problem is to solve (x+2)/(x+1) -2 < 0 and the attempted solution involved finding the LCD of x+1 and simplifying the expression to (-x)/(x+1) < 0. However, the correct solution is (-∞, -1) U (0, ∞) and not (4, 7]. Additionally, the problem is a rational equality, not an absolute inequality.
  • #1
priscilla98
93
0

Homework Statement



Solve (x+2)/(x+1) -2 < 0

Homework Equations



LCD: x + 1

The Attempt at a Solution



(x+2-2x-2)/(x+1) < 0

(-x )/(x+1) < 0

But somehow, I got the wrong answer. The answer is (4, 7]. But I don't know where I went wrong.
 
Physics news on Phys.org
  • #2
I tried everything I could to answer this problem. Am i right that the lcd is x + 1? Because when i multiply - 2 by x + 1, i end up having to cross out + 2 and -2.
 
  • #3
I'm confused because you title this thread "Absolute Value Inequalities," but your problem does not have any absolute value symbols. Can you double check the problem, please? Is the problem this?
[tex]\frac{x+2}{x+1} -2 < 0[/tex]
Because that's what I'm interpreting.

Furthermore, according to WolframAlpha, the solution to what I typed above is
(-∞, -1) U (0, ∞), not (4, 7].69
 
  • #4


Your right, its not absolute inequalities. It's rational equalities.

Okay, thanks a lot for answering this question. I really do appreciate it.
 

What is an absolute value inequality?

An absolute value inequality is an equation that contains an absolute value expression and a relational operator, such as <, >, ≤, or ≥. It represents a range of values that satisfy the inequality, rather than a single solution.

How do I solve absolute value inequalities?

To solve an absolute value inequality, isolate the absolute value expression on one side of the equation and remove the absolute value bars. Then, create two separate equations, one with a positive number on the other side of the inequality sign, and one with a negative number. Solve each equation separately and combine the solutions to find the range of values that satisfy the inequality.

What is the difference between solving absolute value equations and inequalities?

Solving absolute value equations means finding the specific value or values that make the equation true, while solving absolute value inequalities means finding a range of values that make the inequality true. This is because inequalities represent a larger set of solutions than equations.

Can absolute value inequalities have more than one solution?

Yes, absolute value inequalities can have multiple solutions. This is because the absolute value expression can result in a positive or negative value, and each value can satisfy the inequality. Therefore, it is important to check all solutions to ensure they are valid.

How can absolute value inequalities be applied in real-life situations?

Absolute value inequalities can be used to represent a range of values in real-life situations, such as measuring temperatures, distances, or prices. They can also be used in optimization problems, where a certain value must be within a specific range. For example, a company may need to keep their production costs within a certain range to be profitable.

Similar threads

  • Precalculus Mathematics Homework Help
Replies
11
Views
1K
  • Precalculus Mathematics Homework Help
Replies
9
Views
764
  • Precalculus Mathematics Homework Help
Replies
11
Views
1K
  • Precalculus Mathematics Homework Help
Replies
3
Views
770
  • Precalculus Mathematics Homework Help
Replies
7
Views
722
  • Precalculus Mathematics Homework Help
Replies
5
Views
122
  • Precalculus Mathematics Homework Help
Replies
10
Views
930
  • Precalculus Mathematics Homework Help
Replies
7
Views
1K
  • Precalculus Mathematics Homework Help
Replies
2
Views
857
  • Precalculus Mathematics Homework Help
Replies
7
Views
878
Back
Top