Math Problem Statement

4/x - 5/x+3 =1

Solution

To solve the equation:

4x5x+3=1\frac{4}{x} - \frac{5}{x+3} = 1

Step 1: Eliminate the denominators

Multiply through by the least common denominator (LCD), which is x(x+3)x(x+3), to get rid of the fractions:

x(x+3)(4x5x+3)=x(x+3)1x(x+3) \cdot \left( \frac{4}{x} - \frac{5}{x+3} \right) = x(x+3) \cdot 1

Simplifying each term:

4(x+3)5x=x(x+3)4(x+3) - 5x = x(x+3)

Step 2: Expand both sides

Expand both sides of the equation:

4x+125x=x2+3x4x + 12 - 5x = x^2 + 3x

Step 3: Simplify the equation

Combine like terms on the left side:

x+12=x2+3x-x + 12 = x^2 + 3x

Step 4: Move all terms to one side

Rearrange the equation to form a quadratic equation:

x2+3x+x12=0x^2 + 3x + x - 12 = 0

This simplifies to:

x2+4x12=0x^2 + 4x - 12 = 0

Step 5: Solve the quadratic equation

Use the quadratic formula to solve for xx, where a=1a = 1, b=4b = 4, and c=12c = -12:

x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

Substitute the values of aa, bb, and cc:

x=4±424(1)(12)2(1)x = \frac{-4 \pm \sqrt{4^2 - 4(1)(-12)}}{2(1)}

x=4±16+482x = \frac{-4 \pm \sqrt{16 + 48}}{2}

x=4±642x = \frac{-4 \pm \sqrt{64}}{2}

x=4±82x = \frac{-4 \pm 8}{2}

This gives two solutions:

x=4+82=2orx=482=6x = \frac{-4 + 8}{2} = 2 \quad \text{or} \quad x = \frac{-4 - 8}{2} = -6

Step 6: Check for extraneous solutions

Substitute both values of xx back into the original equation to ensure they are valid solutions.

  • For x=2x = 2:
    4252+3=1\frac{4}{2} - \frac{5}{2+3} = 1 21=1(Valid solution)2 - 1 = 1 \quad \text{(Valid solution)}

  • For x=6x = -6:
    4656+3=1\frac{4}{-6} - \frac{5}{-6+3} = 1 This results in division by zero, so x=6x = -6 is not a valid solution.

Final Answer:

The solution is:

x=2x = 2

Do you want more details or have any questions?

Here are 5 related questions:

  1. How do you solve quadratic equations using factorization?
  2. What is the quadratic formula and how is it derived?
  3. How can you check if a quadratic equation has real or complex solutions?
  4. What is an extraneous solution and why does it occur?
  5. How do you solve rational equations without the quadratic formula?

Tip: Always check your solutions in the original equation, especially for rational equations, to avoid extraneous solutions.

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Math Problem Analysis

Mathematical Concepts

Rational Equations
Algebra
Quadratic Equations
Extraneous Solutions

Formulas

Quadratic formula: x = [-b ± sqrt(b² - 4ac)] / 2a
Least Common Denominator (LCD)

Theorems

Quadratic formula
Extraneous solutions in rational equations

Suitable Grade Level

Grades 9-10