Solve For { P $} : : : { 4^{2p} = 8^{-2p-1} \}

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Introduction

Exponential equations are a fundamental concept in mathematics, and solving them requires a deep understanding of the underlying principles. In this article, we will focus on solving the equation 42p=8βˆ’2pβˆ’14^{2p} = 8^{-2p-1}, which involves manipulating exponential expressions and applying logarithmic properties. By the end of this discussion, you will have a clear understanding of how to approach and solve similar exponential equations.

Understanding Exponential Equations

Exponential equations involve variables in the exponent, and they can be written in the form ax=ba^x = b, where aa is the base, xx is the exponent, and bb is the result. In the given equation, 42p4^{2p} and 8βˆ’2pβˆ’18^{-2p-1} are both exponential expressions, and we need to find the value of pp that makes them equal.

Step 1: Simplify the Equation

To simplify the equation, we can start by expressing both sides with the same base. Since 44 and 88 are both powers of 22, we can rewrite the equation as follows:

(22)2p=(23)βˆ’2pβˆ’1\left(2^2\right)^{2p} = \left(2^3\right)^{-2p-1}

Using the property of exponents that (am)n=amn(a^m)^n = a^{mn}, we can simplify the equation further:

24p=2βˆ’6pβˆ’32^{4p} = 2^{-6p-3}

Step 2: Equate the Exponents

Since the bases are the same, we can equate the exponents:

4p=βˆ’6pβˆ’34p = -6p-3

Step 3: Solve for p

To solve for pp, we can add 6p6p to both sides of the equation:

10p=βˆ’310p = -3

Then, we can divide both sides by 1010:

p=βˆ’310p = -\frac{3}{10}

Conclusion

Solving the equation 42p=8βˆ’2pβˆ’14^{2p} = 8^{-2p-1} required us to simplify the equation, equate the exponents, and solve for pp. By following these steps, we were able to find the value of pp that makes the equation true. This process can be applied to similar exponential equations, and it is essential to understand the underlying principles of exponents and logarithms.

Tips and Tricks

  • When solving exponential equations, it is essential to simplify the equation by expressing both sides with the same base.
  • Equating the exponents is a crucial step in solving exponential equations.
  • Solving for the variable requires careful manipulation of the equation.

Real-World Applications

Exponential equations have numerous real-world applications, including:

  • Finance: Exponential equations are used to calculate compound interest and investment returns.
  • Science: Exponential equations are used to model population growth, chemical reactions, and other phenomena.
  • Engineering: Exponential equations are used to design and optimize systems, such as electrical circuits and mechanical systems.

Common Mistakes

  • Failing to simplify the equation by expressing both sides with the same base.
  • Equating the wrong exponents or variables.
  • Not checking the solution for extraneous solutions.

Practice Problems

  1. Solve the equation 32x=9βˆ’xβˆ’13^{2x} = 9^{-x-1}.
  2. Solve the equation 23x=8xβˆ’22^{3x} = 8^{x-2}.
  3. Solve the equation 5xβˆ’2=252x+15^{x-2} = 25^{2x+1}.

Solutions

  1. x=βˆ’12x = -\frac{1}{2}
  2. x=14x = \frac{1}{4}
  3. x=βˆ’32x = -\frac{3}{2}