SolveMathAI

Solve log base 2 of x plus log base 2 of (x - 2) = 3

Worked through step by step. More algebra.

Answer
4\boxed{4}

Substituting x=4x = 4 back into the original equation gives log2(4)+log2(2)=2+1=3\log_2(4) + \log_2(2) = 2 + 1 = 3, which is correct.

Problem: Solve for xx: log2(x)+log2(x2)=3\log_2(x) + \log_2(x - 2) = 3

Steps

  1. Combine logarithms using the product rule
    log2(x(x2))=3\log_2(x(x - 2)) = 3
  2. Rewrite the logarithmic equation as an exponential equation
    x(x2)=23x(x - 2) = 2^3
  3. Simplify the right side
    x(x2)=8x(x - 2) = 8
  4. Distribute on the left side
    x22x=8x^2 - 2x = 8
  5. Subtract 8 from both sides to form a quadratic equation
    x22x8=0x^2 - 2x - 8 = 0
  6. Factor the quadratic equation
    (x4)(x+2)=0(x - 4)(x + 2) = 0
  7. Solve for xx
    x=4orx=2x = 4 \quad \text{or} \quad x = -2
  8. Check for extraneous solutions in the original domain (x>2x > 2)
    For x=2,log2(2) is undefined, so x=2 is rejected. For x=4, both terms are valid.\text{For } x = -2, \log_2(-2) \text{ is undefined, so } x = -2 \text{ is rejected. For } x = 4, \text{ both terms are valid.}

Generated by SolveMath AI and kept here so the next person asking gets it instantly. AI can make mistakes, so check anything that matters.

Solve your own

Same solver, same steps, no account.

Enter to solve · Shift+Enter for a new line

  • Free
  • No account
  • Every step shown
  • Arithmetic to calculus

More solved problems

Algebra solver →