Solve the logarithmic equation log 2 6 - x 3 - ... - JAMB Mathematics 2023 Question
Solve the logarithmic equation: \(log_2 (6 - x) = 3 - log_2 x\)
\(x\) = 4 or 2
\(x\) = -4 or -2
\(x\) = -4 or 2
\(x\) = 4 or -2
Let's solve the logarithmic equation:
\[ \log_2(6 - x) = 3 - \log_2(x) \]
First, combine the logarithmic terms on the right side:
\[ \log_2(6 - x) + \log_2(x) = 3 \]
Now, use the product rule of logarithms (\(\log_a(b) + \log_a(c) = \log_a(b \cdot c)\)):
\[ \log_2[(6 - x) \cdot x] = 3 \]
Next, simplify the expression inside the logarithm:
\[ \log_2(6x - x^2) = 3 \]
Now, rewrite the equation in exponential form:
\[ 2^3 = 6x - x^2 \]
\[ 8 = 6x - x^2 \]
Bring all terms to one side to form a quadratic equation:
\[ x^2 - 6x + 8 = 0 \]
Now, factor the quadratic:
\[ (x - 4)(x - 2) = 0 \]
Set each factor equal to zero:
\[ x - 4 = 0 \] or \[ x - 2 = 0 \]
So, the solutions are:
\[ x = 4 \] or \[ x = 2 \]
Therefore, the correct answer is \(x = 4\) or \(x = 2\)
Add your answer
No responses