Chapter 0: Problem 56
Use the properties of exponents to simplify each expression. (See Examples \(3-6)\) $$ \left(-\frac{1}{3}-\frac{1}{4}+\frac{1}{2}\right)^{-2} $$
Short Answer
Expert verified
144
Step by step solution
01
Simplify the Expression Inside the Parentheses
First, combine the fractions inside the parentheses. Start by finding a common denominator for the fractions \(-\frac{1}{3}, -\frac{1}{4}, \text{and} \frac{1}{2}\). The common denominator for 3, 4, and 2 is 12.Rewrite each fraction with the common denominator:\[-\frac{1}{3} = -\frac{4}{12}\]\[-\frac{1}{4} = -\frac{3}{12}\]\[\frac{1}{2} = \frac{6}{12}\]Combine these results:\[-\frac{4}{12} - \frac{3}{12} + \frac{6}{12} = -\frac{4}{12} - \frac{3}{12}+ \frac{6}{12}= -\frac{1}{12}\]
02
Simplify the Parentheses
With the combined result of the fractions, the expression now looks like this:\[(-\frac{1}{12})^{-2}\]
03
Apply the Negative Exponent Rule
Recall that for any expression \(a^{-n} = \frac{1}{a^n}\). Use this rule to simplify \((-\frac{1}{12})^{-2}\):\[\left(-\frac{1}{12}\right)^{-2} = \frac{1}{(-\frac{1}{12})^2}\]
04
Simplify the denominator
Compute the square of the denominator:\[\left(-\frac{1}{12}\right)^2 = \frac{1}{144}\]Thus, the expression becomes \[\frac{1}{\frac{1}{144}} = 144\]
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Simplifying Fractions
To simplify expressions involving fractions, we need to combine them into a single fraction. Here, you'll often start by finding a common denominator. The common denominator is a shared multiple of the denominators of the fractions. For example, in the given exercise, the fractions \(-\frac{1}{3}\), \(-\frac{1}{4}\), and \(\frac{1}{2}\) were combined by using 12 as the common denominator. This process allows us to rewrite each fraction so they can be easily added or subtracted.
To recap, you should:
This results in a single simplified fraction, which is essential for further operations.
To recap, you should:
- Find the least common denominator of the fractions involved
- Convert each fraction to an equivalent fraction with this common denominator
- Add or subtract the numerators, keeping the common denominator
This results in a single simplified fraction, which is essential for further operations.
Negative Exponents
Negative exponents might seem tricky, but they're simpler than they appear. A negative exponent indicates that you should take the reciprocal of the base and then apply the positive exponent. For instance, \(a^{-n} = \frac{1}{a^n}\).
In the provided solution, the expression \((- \frac{1}{12})^{-2}\) transforms into \(\frac{1}{(-\frac{1}{12})^2}\) by applying this rule. This step is crucial because it breaks down the problem into a more manageable form, essentially turning a negative exponent into a positive one by flipping the base.
Always remember:
In the provided solution, the expression \((- \frac{1}{12})^{-2}\) transforms into \(\frac{1}{(-\frac{1}{12})^2}\) by applying this rule. This step is crucial because it breaks down the problem into a more manageable form, essentially turning a negative exponent into a positive one by flipping the base.
Always remember:
- A negative exponent means 'reciprocal'.
- Convert the base to its reciprocal and then perform the exponentiation as usual
Common Denominator
A key part of working with fractions is finding a common denominator. This is particularly useful when adding or subtracting fractions, as it ensures all fractions are on a level playing field.
In our example, the common denominator for 3, 4, and 2 is 12. Each fraction was then rewritten with 12 as the denominator:
This step is critical because it allows the fractions to be easily combined.
A few steps to find a common denominator:
Mastering common denominators will unlock many more advanced fractional operations.
In our example, the common denominator for 3, 4, and 2 is 12. Each fraction was then rewritten with 12 as the denominator:
- \(- \frac{1}{3} = - \frac{4}{12}\)
- \(- \frac{1}{4} = - \frac{3}{12}\)
- \( \frac{1}{2} = \frac{6}{12}\)
This step is critical because it allows the fractions to be easily combined.
A few steps to find a common denominator:
- Identify the least common multiple (LCM) of the denominators
- Rewrite each fraction to have this common denominator by multiplying the numerator and denominator by the same number
- Proceed with the addition or subtraction of the fractions
Mastering common denominators will unlock many more advanced fractional operations.