Math Problem Statement

Solve the equation 2 log_3(X) - log_3(4X) = 2.

Solution

The given equation is:

2log3Xlog34X=22 \log_3 X - \log_3 4X = 2

Step 1: Use logarithmic properties

Recall the following logarithmic rules:

  1. alogbM=logbMaa \log_b M = \log_b M^a
  2. logbMlogbN=logb(MN)\log_b M - \log_b N = \log_b \left(\frac{M}{N}\right)

Apply these rules to simplify the left-hand side: 2log3X=log3X22 \log_3 X = \log_3 X^2 log3X2log34X=log3(X24X)\log_3 X^2 - \log_3 4X = \log_3 \left(\frac{X^2}{4X}\right)

Simplify the fraction: X24X=X4\frac{X^2}{4X} = \frac{X}{4}

Thus, the equation becomes: log3(X4)=2\log_3 \left(\frac{X}{4}\right) = 2

Step 2: Exponentiate to remove the logarithm

If logbM=N\log_b M = N, then M=bNM = b^N. Apply this to the equation: X4=32\frac{X}{4} = 3^2

Simplify: X4=9\frac{X}{4} = 9

Multiply through by 4: X=36X = 36

Final Answer:

X=36X = 36

Would you like me to go over the properties of logarithms used here or any specific steps?


Questions for Practice:

  1. How do you solve logarithmic equations involving addition instead of subtraction?
  2. Can you verify if X=36X = 36 satisfies the original equation?
  3. What happens if the base of the logarithm is different (e.g., log5\log_5)?
  4. How do you solve loga(M)=loga(N)\log_a (M) = \log_a (N)?
  5. How can logarithmic equations be graphed?

Tip:

Always check the domain of the logarithmic function to ensure that the solution is valid (logarithms are undefined for non-positive arguments).

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Math Problem Analysis

Mathematical Concepts

Logarithms
Algebra
Logarithmic Equations

Formulas

a log_b(M) = log_b(M^a)
log_b(M) - log_b(N) = log_b(M / N)
If log_b(M) = N, then M = b^N

Theorems

Properties of Logarithms
Exponentiation to Solve Logarithmic Equations

Suitable Grade Level

Grades 10-12