- Express both sides of the equation using the same base, noting that \(16 = 2^4\).
- Simplify the left side to \((2^4)^{2x+3} = 2^{8x+12}\) using exponent laws.
- Equate the exponents of the common base: \(8x + 12 = 3x + 2\).
- Solve the linear equation to find \(\boxed{-2}\).
Explanation
- Analyzing the Problem and Expressing Common Bases
We are given the exponential equation \(16^{2x+3} = 2^{3x+2}\). To solve for \(x,\) we should first express both sides of the equation with a common base. Since \(16\) is a power of \(2\), we can write \(16 = 2^4\). By substituting this into the equation, we can convert both sides into expressions with the base \(2\).
- Rewriting the Equation using Exponent Rules
Replacing \(16\) with \(2^4\), the left side becomes \((2^4)^{2x+3}\). According to the power of a power rule in exponents, \((a^m)^n = a^{m \cdot n}\), so we have:
\[(2^4)^{2x+3} = 2^{4(2x+3)} = 2^{8x+12}.\]
Now the equation is:
\[2^{8x+12} = 2^{3x+2}.\]
- Equating the Exponents
Since the bases on both sides are now identical (\(2\)), their exponents must be equal for the equation to hold true. Therefore, we can set the exponents equal to each other:
\[8x + 12 = 3x + 2.\]
- Solving for x
Now we solve for \(x\) by isolating the variable on one side. Subtract \(3x\) from both sides:
\[8x - 3x + 12 = 2\]
\[5x + 12 = 2\]
Next, subtract \(12\) from both sides:
\[5x = 2 - 12\]
\[5x = -10\]
Finally, divide by \(5\):
\[x = \frac{-10}{5} = -2.\]
- Verification and Final Conclusion
To verify our result, substitute \(x = -2\) back into the original equation:
Left side: \(16^{2(-2)+3} = 16^{-4+3} = 16^{-1} = \frac{1}{16}\).
Right side: \(2^{3(-2)+2} = 2^{-6+2} = 2^{-4} = \frac{1}{2^4} = \frac{1}{16}\).
Since both sides equal \(\frac{1}{16}\), our solution \(x = -2\) is correct. Thus, the final value is \(\boxed{-2}\).
Examples
Exponential equations are essential for understanding growth and decay, such as calculating the time it takes for a savings account with compound interest to reach a certain value, or modeling population growth over time. For example, if a company's profit doubles every year, you can model their growth with an exponential equation to determine when they will reach a specific target, much like finding the value of \(x\) in the equation above. Mastering these algebraic techniques provides a foundation for solving these real-world problems.