Math Problem Statement

The equation \(\frac{12x^2 + 6x - 23}{bx - 3} = -2x - \frac{23}{bx - 3}\) is true for all values of \(x \neq \frac{3}{b}\). What is the value of \(b\)?

Solution

Let's solve the problem.

We are given the equation:

12x2+6x23bx3=2x23bx3,\frac{12x^2 + 6x - 23}{bx - 3} = -2x - \frac{23}{bx - 3},

and need to determine the value of bb such that this equation holds for all x3bx \neq \frac{3}{b}.


Step-by-Step Solution:

1. Eliminate the denominator bx3bx - 3

Multiply through by bx3bx - 3, which is valid for x3bx \neq \frac{3}{b}:

12x2+6x23=(2x)(bx3)23.12x^2 + 6x - 23 = (-2x)(bx - 3) - 23.


2. Expand the terms on the right-hand side:

Distribute 2x-2x on the right-hand side:

12x2+6x23=2xbx+6x23.12x^2 + 6x - 23 = -2x \cdot bx + 6x - 23.

Simplify:

12x2+6x23=2bx2+6x23.12x^2 + 6x - 23 = -2bx^2 + 6x - 23.


3. Compare coefficients of x2x^2, xx, and constants:

Since this equation must hold for all xx, compare the coefficients of x2x^2, xx, and the constant term:

  • Coefficient of x2x^2: 12=2b12 = -2b, so: b=6.b = -6.

  • Coefficient of xx: 6=66 = 6 (this matches, so it's consistent).

  • Constant term: 23=23-23 = -23 (this also matches).


Final Answer:

The value of bb is:

6.\boxed{-6}.


Would you like a detailed explanation of any step? 😊

Related Questions:

  1. How do we compare coefficients to solve equations?
  2. What happens if b=0b = 0 in the given equation?
  3. Can you generalize this approach for equations with similar fractions?
  4. How does multiplying by the denominator affect the equation?
  5. What restrictions does x3bx \neq \frac{3}{b} impose on the solution?

Tip:

When solving equations involving fractions, always consider restrictions on the variable due to denominators before simplifying!

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Math Problem Analysis

Mathematical Concepts

Algebra
Rational Equations
Coefficient Comparison

Formulas

\(ax^2 + bx + c = 0\)
Coefficient Matching

Theorems

Polynomial Identity Theorem

Suitable Grade Level

Grades 9-12