Solve: log₉(e³) × (log₂24 - log₂8) × ln(8×2) | Complete Logarithm Problem

Question

log9e3×(log224log28)(ln8+ln2) \log_9e^3\times(\log_224-\log_28)(\ln8+\ln2)

Video Solution

Solution Steps

00:00 Solve
00:11 We'll use the logarithm subtraction formula, we'll get their logarithm
00:21 We'll use this formula in our exercise
00:31 We'll use the logarithm addition formula, we'll get the logarithm of their product
00:36 We'll use this formula in our exercise
01:01 We'll use the logarithm multiplication formula, we'll switch between the numbers
01:21 We'll use this formula in our exercise
01:36 We'll use the formula to convert from ln to log
01:40 We'll use this formula in our exercise
01:55 Again we'll use the logarithm multiplication formula
02:04 We'll calculate the logarithm and substitute it in the exercise
02:34 We'll calculate this logarithm and substitute it in the exercise
02:59 We'll calculate the final logarithm and substitute it in the exercise
03:09 We'll solve the multiplications
03:19 And this is the solution to the question

Step-by-Step Solution

We will solve the problem step by step:

Step 1: Simplify log9e3\log_9 e^3

  • Using the change of base formula, log9e3=lne3ln9\log_9 e^3 = \frac{\ln e^3}{\ln 9}.
  • We know lne3=3lne=3\ln e^3 = 3\ln e = 3, because lne=1\ln e = 1.
  • Thus, log9e3=3ln9=32ln3\log_9 e^3 = \frac{3}{\ln 9} = \frac{3}{2\ln 3}, since ln9=2ln3\ln 9 = 2\ln 3.
  • Therefore, log9e3=32ln3\log_9 e^3 = \frac{3}{2\ln 3}.

Step 2: Simplify log224log28\log_2 24 - \log_2 8

  • Use the logarithm subtraction rule: log224log28=log2(248)=log23\log_2 24 - \log_2 8 = \log_2 \left(\frac{24}{8}\right) = \log_2 3.

Step 3: Simplify ln8+ln2\ln 8 + \ln 2

  • Using the product property of logarithms: ln8+ln2=ln(8×2)=ln16\ln 8 + \ln 2 = \ln(8 \times 2) = \ln 16.
  • Since 16=2416 = 2^4, ln16=4ln2\ln 16 = 4\ln 2.

Step 4: Combine the results

  • We need to check the overall structure: log9e3×log23×4ln2\log_9 e^3 \times \log_2 3 \times 4 \ln 2.
  • Previously calculated: log9e3=32ln3\log_9 e^3 = \frac{3}{2 \ln 3}, log23=ln3ln2\log_2 3 = \frac{\ln 3}{\ln 2}.
  • Therefore, the entire expression becomes:
  • 32ln3×ln3ln2×4ln2=32×4=6\frac{3}{2 \ln 3} \times \frac{\ln 3}{\ln 2} \times 4 \ln 2 = \frac{3}{2} \times 4 = 6.

Therefore, the solution to the problem is 6 6 .

Answer

6 6


More Questions