Math Problem Statement

log base 2 (x-1) + 1 = Log base 2 (x+3)

Solution

Let's solve the equation:

log2(x1)+1=log2(x+3)\log_2{(x-1)} + 1 = \log_2{(x+3)}

Step 1: Isolate the logarithmic terms.

First, subtract 1 from both sides:

log2(x1)=log2(x+3)1\log_2{(x-1)} = \log_2{(x+3)} - 1

Step 2: Express the 1 as a logarithm.

We know that 1=log221 = \log_2{2}, so:

log2(x1)=log2(x+3)log22\log_2{(x-1)} = \log_2{(x+3)} - \log_2{2}

Step 3: Use the logarithm subtraction rule.

The subtraction of logarithms can be expressed as the logarithm of a division:

log2(x1)=log2(x+32)\log_2{(x-1)} = \log_2{\left(\frac{x+3}{2}\right)}

Step 4: Set the arguments equal to each other.

Since the logarithms are equal, their arguments must be equal:

x1=x+32x - 1 = \frac{x + 3}{2}

Step 5: Solve the equation.

Multiply both sides by 2 to eliminate the fraction:

2(x1)=x+32(x - 1) = x + 3

Expand and simplify:

2x2=x+32x - 2 = x + 3

Subtract xx from both sides:

x2=3x - 2 = 3

Add 2 to both sides:

x=5x = 5

Step 6: Check the solution.

Substitute x=5x = 5 back into the original equation:

log2(51)+1=log2(5+3)\log_2{(5-1)} + 1 = \log_2{(5+3)}

log24+1=log28\log_2{4} + 1 = \log_2{8}

log24=2\log_2{4} = 2 and log28=3\log_2{8} = 3:

2+1=32 + 1 = 3

The equation holds true, so the solution is:

5\boxed{5}

Would you like more details on any step, or do you have any questions?


Here are five related questions:

  1. How do you solve logarithmic equations with different bases?
  2. What are the properties of logarithms that are essential for solving equations?
  3. Can you solve log2(x21)=log2(x+2)\log_2{(x^2-1)} = \log_2{(x+2)}?
  4. What happens if there is no solution to a logarithmic equation?
  5. How do you solve an equation where logarithms appear on both sides with different coefficients?

Tip: Always check your solutions by substituting them back into the original equation, especially with logarithmic equations, to ensure they don't result in taking the logarithm of a non-positive number.

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Math Problem Analysis

Mathematical Concepts

Logarithms
Equations

Formulas

Logarithm subtraction rule

Theorems

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Suitable Grade Level

Grades 10-12