Chapter 5: Problem 70
Use the distributive property to help simplify each of the following. All variables represent positive real numbers. \(4 \sqrt{8 n}+3 \sqrt{18 n}-2 \sqrt{72 n}\)
Short Answer
Expert verified
The simplified form is \(5\sqrt{2n}\).
Step by step solution
01
Simplify Each Inside the Radical
First, simplify each term by breaking down the number inside the square root into its prime factors. For \( \sqrt{8n} \), express 8 as \( 2^3 \); for \( \sqrt{18n} \), express 18 as \( 2 \times 3^2 \); and for \( \sqrt{72n} \), express 72 as \( 2^3 \times 3^2 \).
02
Apply the Square Root to Factors
Now apply the square root to the factors. For \( \sqrt{8n} \), it becomes \( \sqrt{2^3 \cdot n} = 2\sqrt{2n} \); for \( \sqrt{18n} \), it becomes \( \sqrt{2 \cdot 3^2 \cdot n} = 3\sqrt{2n} \); and for \( \sqrt{72n} \), it becomes \( \sqrt{(2^3)(3^2)n} = 6\sqrt{2n} \).
03
Multiply by Coefficients
Multiply each simplified version by its original coefficient: \(4 \times 2\sqrt{2n} = 8\sqrt{2n}\), \(3 \times 3\sqrt{2n} = 9\sqrt{2n}\), and \( -2 \times 6\sqrt{2n} = -12\sqrt{2n}\).
04
Combine Like Terms
Now, add or subtract the terms since they all simplify to terms involving \( \sqrt{2n} \): \( 8\sqrt{2n} + 9\sqrt{2n} - 12\sqrt{2n} = (8 + 9 - 12) \sqrt{2n}\).
05
Calculate the Final Answer
Perform the arithmetic inside the parentheses: \( (8 + 9 - 12) \sqrt{2n} = 5\sqrt{2n} \). So the simplified form is \( 5\sqrt{2n} \).
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 Radicals
Simplifying radicals means making a square root expression as simple as possible. This involves finding the prime factors of the number under the square root (radicand) and simplifying those. Consider \( \sqrt{8n} \) as an example. We break down 8 into its prime factors: \( 8 = 2^3 \). This expression can be rewritten as \( \sqrt{2^3 \cdot n} \).
- Take out pairs of prime factors from under the radical sign. A pair of \( 2^2 \) taken out becomes a single 2 in front of the square root.
- This results in \( 2 \sqrt{2n} \).
Square Roots
Square roots are fundamental in algebra. They tell us what number times itself equals the given number. For our problem, handling radicals like \( \sqrt{8n} \), \( \sqrt{18n} \), and \( \sqrt{72n} \) is key. Each needs its components simplified by applying square root rules.
- For example, \( \sqrt{8n} \) becomes \( 2 \sqrt{2n} \) once simplified.
- Likewise, \( \sqrt{18n} \) leads to \( 3 \sqrt{2n} \), and \( \sqrt{72n} \) simplifies to \( 6 \sqrt{2n} \).
Prime Factorization
Prime factorization is breaking down a number into a product of its prime numbers. This is essential when simplifying expressions like square roots. For instance, factorize the number 18 in \( \sqrt{18n} \).
- 18 breaks down as \( 2 \times 3^2 \).
- Similarly, 72 in \( \sqrt{72n} \) turns into \( 2^3 \times 3^2 \).
Combining Like Terms
Combining like terms refers to summing or subtracting terms with the same variable factor and exponent. In our exercise, once simplified, we have expressions like \( 8\sqrt{2n} \), \( 9\sqrt{2n} \), and \( -12\sqrt{2n} \). These can be combined because they involve the same radical part \( \sqrt{2n} \).
- Add or subtract their coefficients: \( 8 + 9 - 12 \).
- Resulting in: \( 5 \sqrt{2n} \).