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Start by stating the excluded values. These are the values for which the denominator is 0 in any fraction of the related rational equation.
- 4 < x < 3
To solve the given rational inequality, we will follow four steps.
Let's deal with these steps one at a time.
Consider the given inequality.
3/4-1/x-3 > x/x+4
Let's find the values for which any of the denominators is 0.
We obtain the related equation by replacing the inequality sign with an equals sign. c|c Inequality & Equation [0.8em] 3/4-1/x-3 > x/x+4 & 3/4-1/x-3 = x/x+4 Let's solve the equation. First, we will get rid of all of the denominators.
Now that we have an equation without any denominators, we can simplify it as much as possible.
Distribute 3 & -4 & 4x
Distribute (3x-9)
Distribute x & 4
Add and subtract terms
LHS-3x^2=RHS-3x^2
LHS+x=RHS+x
LHS+52=RHS+52
Rearrange equation
We obtained a quadratic equation. Let's identify the values of a, b, and c. x^2-11x+52=0 ⇕ 1x^2+( - 11)x+ 52=0 We have that a= 1, b= - 11, and c= 52. We will solve this equation by substituting these values into the Quadratic Formula.
Substitute values
- (- a)=a
Calculate power and product
Subtract terms
Since the radicand is a negative number, the equation does not have real solutions.
Since the related equation does not have real solutions, we will divide the number line considering only the excluded values x=- 4 and x=3.
We will now test a value from each interval. Let's start with the interval x<- 4. We will test the point x=- 5. If substituting this point into the original inequality produces a true statement, then the numbers in this interval are solutions. If not, these numbers are not solutions.
x= - 5
Subtract terms
- a/- b= a/b
a/b=a * 2/b * 2
Add fractions
Calculate quotient
Since we obtained a false statement, we can conclude that the numbers less than - 4 are not solutions to the inequality. Using the same process, we can determine whether the numbers that belong to the other intervals are solutions.
| Interval | Test Value | Statement |
|---|---|---|
| x< - 4 | x=- 5 | 0.875>5 * |
| - 4< x < 3 | x=0 | 1.083>0 ✓ |
| x>3 | x=5 | 0.25>0.556 * |
We found that the solutions to the given inequality are all the numbers between - 4 and 3.
Solution
- 4