Chapter 9: Problem 25
Solve each equation. $$ 2^{x^{2}-2 x}=8 $$
Short Answer
Expert verified
The solutions are \( x = 3 \) and \( x = -1 \).
Step by step solution
01
Understand the Equation
The given equation is \( 2^{x^2 - 2x} = 8 \). Notice that 8 can be rewritten as \( 2^3 \), making the equation \( 2^{x^2 - 2x} = 2^3 \).
02
Set the Exponents Equal
Since the bases (2) on both sides of the equation are the same, we can set the exponents equal to each other: \( x^2 - 2x = 3 \).
03
Rearrange the Equation
Bring all terms to one side of the equation: \( x^2 - 2x - 3 = 0 \). This is a standard quadratic equation.
04
Solve the Quadratic Equation
Factor the quadratic equation: \( (x - 3)(x + 1) = 0 \).
05
Find the Solutions
Set each factor equal to zero: \( x - 3 = 0 \) and \( x + 1 = 0 \). Solving these gives the solutions \( x = 3 \) and \( x = -1 \).
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Exponents
Exponents are a fundamental concept in mathematics that involve repeated multiplication. For example, if you have a base number, like 2, raised to an exponent, this means multiplying the base by itself a certain number of times. Let's take a closer look at the problem "\(2^{x^2 - 2x} = 8\)." In this case, the base is 2, and the exponent is \(x^2 - 2x\). Notably, understanding how to manipulate exponents is crucial when both sides of an equation share the same base.
- When equations have the same base, their exponents can be set equal to each other.
- 8 can be expressed as \(2^3\), which is a key step in simplifying the equation.
- Thus, we have \(2^{x^2 - 2x} = 2^3\), allowing us to equate the exponents: \(x^2 - 2x = 3\).
Factoring Quadratics
Factoring quadratics is an essential skill in algebra, especially when dealing with quadratic equations, which are of the form \(ax^2 + bx + c = 0\). Factoring is the process of breaking down a quadratic into the product of simpler expressions, which can then be used to find the variable's solutions.Consider the quadratic equation \(x^2 - 2x - 3 = 0\) derived from equating the exponents. To factor, we look for two numbers that multiply to \(-3\) (the constant term) and add up to \(-2\) (the coefficient of \(x\)).
- The numbers \(-3\) and \(1\) fit these criteria because \(-3 \times 1 = -3\) and \(-3 + 1 = -2\).
- Thus, the equation can be factored into \((x - 3)(x + 1) = 0\).
Solving Equations
Solving equations is all about finding the value(s) of the variable(s) that make the equation true. In the final step of our quadratic problem, after factoring \((x - 3)(x + 1) = 0\), we solve the equation by setting each factor equal to zero.This is based on the zero-product property, which states that if the product of two terms is zero, at least one of the terms must be zero.
- First, set \(x - 3 = 0\). By adding 3 to both sides, we find that \(x = 3\).
- Then, set \(x + 1 = 0\). Subtracting 1 from both sides gives us \(x = -1\).