Solve for x: 5/(2-x) + (x-5)/(x-3) + (3x+8)/(x^2-4) = 0

Question image

Understand the Problem

The question asks to solve an equation involving rational expressions. We will need to find a common denominator, combine the fractions, and then solve for x.

Answer

$x \approx 6.63535$
Answer for screen readers

$x \approx 6.63535$

Steps to Solve

  1. Factor the denominator $x^2 - 4$ We can factor the denominator $x^2 - 4$ as a difference of squares: $x^2 - 4 = (x-2)(x+2)$. Also, rewrite $2-x$ as $-(x-2)$. So the equation becomes: $$ \frac{5}{-(x-2)} + \frac{x-5}{x-3} + \frac{3x+8}{(x-2)(x+2)} = 0 $$ $$ -\frac{5}{x-2} + \frac{x-5}{x-3} + \frac{3x+8}{(x-2)(x+2)} = 0 $$

  2. Find a common denominator The least common denominator (LCD) is $(x-2)(x-3)(x+2)$. Multiply each term to get the LCD in the denominator: $$ -\frac{5(x-3)(x+2)}{(x-2)(x-3)(x+2)} + \frac{(x-5)(x-2)(x+2)}{(x-3)(x-2)(x+2)} + \frac{(3x+8)(x-3)}{(x-2)(x+2)(x-3)} = 0 $$

  3. Combine the numerators Since the denominators are the same, we can combine the numerators: $$ \frac{-5(x-3)(x+2) + (x-5)(x-2)(x+2) + (3x+8)(x-3)}{(x-2)(x-3)(x+2)} = 0 $$

  4. Expand the numerators Expand each term in the numerator: $$ -5(x^2 -x -6) + (x-5)(x^2 - 4) + (3x^2 -x -24) = 0 $$ $$ -5x^2 + 5x + 30 + x^3 - 4x - 5x^2 + 20 + 3x^2 - x - 24 = 0 $$

  5. Simplify the numerator Combine like terms: $$ x^3 + (-5-5+3)x^2 + (5-4-1)x + (30+20-24) = 0 $$ $$ x^3 - 7x^2 + 0x + 26 = 0 $$ $$ x^3 - 7x^2 + 26 = 0 $$

  6. Solve for x

We can observe that $x = -2$ is a solution, since $(-2)^3 - 7(-2)^2 + 26 = -8 - 28 + 26 = -10 \ne 0$. Also, $x = 2$ and $x = 3$ are not allowed. We can also test $x = 1$: $1 - 7 + 26 = 20 \ne 0$. We can test $x = 4$: $64 - 7(16) + 26 = 64 - 112 + 26 = -22 \ne 0$. Using a calculator or numerical method (such as WolframAlpha), we find one real root: $x \approx 6.63535$

  1. Check for extraneous solutions Since the original equation has denominators of $2-x$, $x-3$, and $x^2-4$, we must make sure that the solutions do not make any of these denominators zero. In other words, we must ensure that $x \ne 2$, $x \ne -2$, and $x \ne 3$. Since $x \approx 6.63535$, this condition is satisfied.

Note: Finding the exact solutions to a cubic equation usually involves more advanced techniques or numerical approximations.

$x \approx 6.63535$

More Information

The equation is a cubic equation, which can be solved using numerical methods or advanced algebraic techniques. The approximate solution is found to be near 6.63535.

Tips

A common mistake is not factoring the quadratic term $x^2-4$ correctly or forgetting to check for extraneous solutions at the end. Another mistake may occur when expanding and collecting like terms, which may lead to incorrect coefficients in the cubic equation. Failing to notice that $2-x = -(x-2)$ can complicate the process.

AI-generated content may contain errors. Please verify critical information

Thank you for voting!
Use Quizgecko on...
Browser
Browser