Example

Solving 15x2+x63x2=2x+3\frac{15}{x^2+x-6} - \frac{3}{x-2} = \frac{2}{x+3}

Solve the rational equation 15x2+x63x2=2x+3\frac{15}{x^2+x-6} - \frac{3}{x-2} = \frac{2}{x+3}.

Step 1 — Identify restricted values. Factor the quadratic denominator: x2+x6=(x2)(x+3)x^2+x-6 = (x-2)(x+3). The factors of all denominators are (x2)(x-2) and (x+3)(x+3). Setting them to zero yields the restricted values: x2x \neq 2 and x3x \neq -3.

Step 2 — Find the LCD. The denominators are (x2)(x+3)(x-2)(x+3), (x2)(x-2), and (x+3)(x+3). The LCD is (x2)(x+3)(x-2)(x+3).

Step 3 — Clear the fractions. Multiply every term on both sides by the LCD (x2)(x+3)(x-2)(x+3) and cancel the matching factors: (x2)(x+3)15(x2)(x+3)(x2)(x+3)3x2=(x2)(x+3)2x+3(x-2)(x+3) \cdot \frac{15}{(x-2)(x+3)} - (x-2)(x+3) \cdot \frac{3}{x-2} = (x-2)(x+3) \cdot \frac{2}{x+3} Simplify to obtain the fraction-free equation: 153(x+3)=2(x2)15 - 3(x+3) = 2(x-2)

Step 4 — Solve the resulting equation. Distribute: 153x9=2x415 - 3x - 9 = 2x - 4. Combine like terms: 63x=2x46 - 3x = 2x - 4. Add 3x3x to both sides: 6=5x46 = 5x - 4. Add 44 to both sides: 10=5x10 = 5x. Divide by 55: x=2x = 2.

Step 5 — Check. The algebraic solution x=2x = 2 matches a restricted value identified in Step 1. Because substituting x=2x = 2 into the original equation would result in division by zero, it is an extraneous solution.

Since the only potential algebraic solution is extraneous, the equation has no solution.

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Updated 2026-04-30

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