Technology
Solving the Equation log_2(3-x) log_2(1-x) 3
Solving the Equation log2(3-x) log2(1-x) 3
In this article, we will walk through the process of solving the equation log2(3-x) log2(1-x) 3. We will use the properties of logarithms and basic algebra to find the solution, ensuring that the arguments of the logarithms are positive.
Step-by-Step Solution
Let's start with the given equation:
log2(3-x) log2(1-x) 3
Step 1: Rewrite the Equation
First, let's rewrite the equation by combining the logarithms on the left side using the product property:
log2(3-x)1-x 3
According to the logarithm properties, this can be rewritten as:
3 - x1 - x 23
Step 2: Simplify the Equation
Calculate the right-hand side of the equation:
3 - x1 - x 8
Now, expand the left side of the equation:
3 - 3x - x x2 8
This simplifies to:
x2 - 4x - 3 8
Next, rearrange the equation to form a quadratic equation:
x2 - 4x - 5 0
Step 3: Factor the Quadratic Equation
Factor the quadratic equation:
x2 - 4x - 5 (x - 5)(x 1) 0
This gives us two solutions:
x - 5 0 rarr; x 5
x 1 0 rarr; x -1
Step 4: Check for Valid Solutions
Now we need to check which of these solutions are valid in the original logarithmic expressions. The arguments of the logarithms must be positive:
x 5 3 - 5 -2 (not valid) 1 - 5 -4 (not valid) x -1 3 - (-1) 4 (valid) 1 - (-1) 2 (valid)Since x 5 is not a valid solution, the only valid solution is:
boxed{-1}
Alternative Solutions
Let's also present an alternative approach to solving this equation:
3 - x1 - x 23 8
This gives us:
3 - x1 - x - 8 0
Further simplifying:
x2 - 4x - 5 0
Factoring the quadratic equation:
x2 - 5x x - 5 0
Grouping the factors:
x(x - 5) 1(x - 5) 0
This can be factored as:
(x - 5)(x 1) 0
Setting each factor to zero:
x - 5 0 rarr; x 5
x 1 0 rarr; x -1
Verification
Verify that the solutions are valid:
For x 5:
3 - 5 -2 (not valid) 1 - 5 -4 (not valid)For x -1:
3 - (-1) 4 (valid) 1 - (-1) 2 (valid)Therefore, the only valid solution is:
boxed{-1}