ln(4x+3)−ln(x2−8)=2
?=x
Let's solve the logarithmic equation step-by-step:
Step 1: Combine the Logarithms
Using the property ln(a)−ln(b)=ln(ba), we combine the logarithms:
ln(x2−84x+3)=2
Step 2: Remove the Logarithm by Exponentiation
Exponentiate both sides with base e to get rid of the natural logarithm:
x2−84x+3=e2
Step 3: Solve the Resulting Equation
Multiplying both sides by x2−8 to eliminate the fraction:
4x+3=e2(x2−8)
Expanding and rearranging gives us:
e2x2−4x−8e2−3=0
Let's employ the quadratic formula x=2a−b±b2−4ac, where a=e2, b=−4, and c=−(8e2+3).
Calculate the discriminant:
b2−4ac=(−4)2−4(e2)(−(8e2+3))
Solving this using numerical approximations (since we have e2≈7.39), you get:
x≈3.18
Conclusion:
The value of x is approximately 3.18, which confirms our choice.