Question

Difficulty: MediumRadical and Rational Equations

If xx is a real number that satisfies the equation xx36x23x=2x\frac{x}{x-3} - \frac{6}{x^2-3x} = \frac{2}{x}, what is the value of xx?

Answer: 2

Answer

2
The correct answer is 2. Multiplying the entire equation by the lowest common denominator, x(x3)x(x-3), yields x26=2(x3)x^2 - 6 = 2(x - 3). Distributing the right side gives x26=2x6x^2 - 6 = 2x - 6. Adding 6 to both sides and subtracting 2x2x results in x22x=0x^2 - 2x = 0. Factoring this equation gives x(x2)=0x(x-2) = 0, which has solutions x=0x = 0 and x=2x = 2. However, x=0x = 0 is extraneous because it results in division by zero in the original equation. Thus, the only valid real solution is 2.

Step-by-Step Solution

1
Identify the common denominator and multiply the equation by it.
x26=2(x3)x^2 - 6 = 2(x - 3)
To clear the fractions and simplify the rational equation.
2
Distribute and simplify the equation.
x22x=0x^2 - 2x = 0
To set up the quadratic equation in standard form.
3
Factor and solve for xx.
x=0x = 0 or x=2x = 2
To find potential solutions to the equation.
4
Check for extraneous solutions by substituting the values back into the original denominators.
x=2x = 2
x=0x = 0 makes the denominators equal to zero and is therefore extraneous.

Key Concept

Solving rational equations and identifying extraneous solutions.
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