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A rational equation is an equation that contains at least one rational expression.
Example Solution: 2x-6/x^2-1=1/x+1
We are asked to write a rational equation that has 5 as a solution. Let's start by recalling a few important definitions.
With these definitions in mind, we can write the equation! First, let's arbitrarily choose the variable that we will use to write the equation. We will let x be our variable. We will create our equation by starting from the solution that we want it to have.
x= 5
Remember that we must have at least one rational expression in our equation. Therefore, we will divide both sides of the equation by a polynomial. Let x^2-1 be our polynomial. Note that we have to divide the equation by a polynomial that is not equal to 0 when x= 5. Otherwise, x= 5 will be an extraneous solution.
We can further simplify the right-hand side of the equation by factoring the denominator and canceling any common factors.
a^2-b^2=(a+b)(a-b)
Cancel out common factors
Simplify quotient
We have obtained a rational equation that has 5 as a solution. 2x-6/x^2-1=1/x+1 To be sure, let's check that x= 5 is actually a solution of the equation. This can be done by substituting 5 for x in the equation and simplifying.
x= 5
Calculate power
Multiply
Add and subtract terms
a/b=.a /4./.b /4.
Since the obtained statement is true, x= 5 is a solution of our rational equation. Please note that there are infinitely many rational equations that have 5 as a solution, so our answer is only an example. Here are some other examples.
| Examples |
|---|
| x-5/3x-4=x^2-4x-5 |
| 2x-10/x^2+1=x^2-25/x^3-x^2+3 |
| x+1/2x^2-6=x^2-22/x^2-2x+7 |