Math Problem Statement

Solve question P

Solve question P: 3^(2x) = 3^(x-1) * 2^(4+x)

Solution

To solve question pp:

32x=3x1×24+x3^{2x} = 3^{x-1} \times 2^{4+x}

Step-by-step solution:

  1. Simplify the left-hand side (LHS) and right-hand side (RHS):

    The LHS remains 32x3^{2x}. On the RHS, split it into two bases: 3x1×24+x=3x1×24×2x3^{x-1} \times 2^{4+x} = 3^{x-1} \times 2^4 \times 2^x

    This simplifies to: 3x1×16×2x3^{x-1} \times 16 \times 2^x

    So the equation becomes: 32x=3x1×16×2x3^{2x} = 3^{x-1} \times 16 \times 2^x

  2. Combine powers of 33:

    Rewrite 3x13^{x-1} as: 3x1=3x33^{x-1} = \frac{3^x}{3}

    Substitute this back: 32x=3x3×16×2x3^{2x} = \frac{3^x}{3} \times 16 \times 2^x

    Simplify: 32x=163x2x33^{2x} = \frac{16 \cdot 3^x \cdot 2^x}{3}

    Multiply through by 3 to eliminate the denominator: 332x=163x2x3 \cdot 3^{2x} = 16 \cdot 3^x \cdot 2^x

    So: 32x+1=163x2x3^{2x+1} = 16 \cdot 3^x \cdot 2^x

  3. Rewrite 32x+13^{2x+1}:

    Recall that 32x+1=3x3x+13^{2x+1} = 3^{x} \cdot 3^{x+1}. Substituting this: 3x3x+1=163x2x3^x \cdot 3^{x+1} = 16 \cdot 3^x \cdot 2^x

    Cancel 3x3^x from both sides (assuming 3x03^x \neq 0): 3x+1=162x3^{x+1} = 16 \cdot 2^x

  4. Solve for xx:

    Rewrite 3x+13^{x+1} as 33x3 \cdot 3^x: 33x=162x3 \cdot 3^x = 16 \cdot 2^x

    Divide both sides by 3x3^x: 3=162x3x3 = 16 \cdot \frac{2^x}{3^x}

    Rewrite 2x3x\frac{2^x}{3^x} as (23)x\left(\frac{2}{3}\right)^x: 3=16(23)x3 = 16 \cdot \left(\frac{2}{3}\right)^x

    Divide both sides by 16: 316=(23)x\frac{3}{16} = \left(\frac{2}{3}\right)^x

  5. Take the logarithm of both sides:

    Apply the natural logarithm (ln) to both sides: ln(316)=xln(23)\ln\left(\frac{3}{16}\right) = x \ln\left(\frac{2}{3}\right)

    Solve for xx: x=ln(316)ln(23)x = \frac{\ln\left(\frac{3}{16}\right)}{\ln\left(\frac{2}{3}\right)}

  6. Simplify the logarithms:

    Use the logarithmic property ln(a/b)=ln(a)ln(b)\ln(a/b) = \ln(a) - \ln(b): x=ln(3)ln(16)ln(2)ln(3)x = \frac{\ln(3) - \ln(16)}{\ln(2) - \ln(3)}

    Approximate values:

    • ln(3)1.0986\ln(3) \approx 1.0986
    • ln(16)=ln(24)=4ln(2)40.6931=2.7726\ln(16) = \ln(2^4) = 4 \ln(2) \approx 4 \cdot 0.6931 = 2.7726
    • ln(2)0.6931\ln(2) \approx 0.6931

    Substitute: x=1.09862.77260.69311.0986x = \frac{1.0986 - 2.7726}{0.6931 - 1.0986}

    Simplify the numerator and denominator: x=1.67400.4055x = \frac{-1.6740}{-0.4055}

    Compute: x4.13x \approx 4.13

Final Answer:

x4.13x \approx 4.13


Would you like a detailed breakdown of any step or further clarification?

Related Questions:

  1. How does the base logarithm choice affect solving exponential equations?
  2. How do you rewrite exponential expressions like 3x13^{x-1}?
  3. What are logarithmic properties used in this solution?
  4. Can this equation be solved graphically instead of algebraically?
  5. How do we interpret x4.13x \approx 4.13 in a practical context?

Tip:

When solving equations involving multiple exponential terms, always try to express all terms in similar bases to simplify calculations.

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Math Problem Analysis

Mathematical Concepts

Exponential Equations
Logarithms
Simplifying Expressions

Formulas

Logarithmic identity: ln(a/b) = ln(a) - ln(b)
Exponential rules: a^(m+n) = a^m * a^n
Exponential-to-logarithmic conversion

Theorems

Properties of Logarithms
Equality of Exponents

Suitable Grade Level

Grades 10-12