Chapter 3: Problem 7
Simplify the expression. a. \(\left(64 x^{9}\right)^{1 / 3}\) b. \(\left(25 x^{3} y^{4}\right)^{1 / 2}\)
Short Answer
Expert verified
The simplified expressions are:
a. \(\left(64 x^{9}\right)^{1 / 3} = 4x^{3}\)
b. \(\left(25 x^{3} y^{4}\right)^{1 / 2} = 5x^{\frac{3}{2}}y^2\)
Step by step solution
01
Apply the power to a power rule to each term.
We have two terms inside the brackets: \(64\) and \(x^{9}\). Apply the power to a power rule: \((64)^{1 / 3} \cdot (x^{9})^{1 / 3}\).
02
Simplify each term separately.
Now, we simplify each term:
- \((64)^{1 / 3}\) is the cube root of \(64\), which equals \(4\).
- \((x^{9})^{1 / 3}\) simplifies to \(x^{(9 \cdot \frac{1}{3})}\) = \(x^{3}\).
03
Combine the simplified terms for the answer.
Combine the simplified terms: \(4 \cdot x^{3}\).
So, \(\left(64 x^{9}\right)^{1 / 3} = 4x^{3}\).
b. Simplify \(\left(25 x^{3} y^{4}\right)^{1 / 2}\):
04
Apply the power to a power rule to each term.
We have three terms inside the brackets: \(25\), \(x^{3}\), and \(y^4\). Apply the power to a power rule: \((25)^{1 / 2} \cdot (x^{3})^{1 / 2} \cdot (y^{4})^{1 / 2}\).
05
Simplify each term separately.
Now, we simplify each term:
- \((25)^{1 / 2}\) is the square root of \(25\), which equals \(5\).
- \((x^{3})^{1 / 2}\) simplifies to \(x^{(3 \cdot \frac{1}{2})}\) = \(x^{\frac{3}{2}}\).
- \((y^{4})^{1 / 2}\) simplifies to \(y^{(4 \cdot \frac{1}{2})}\) = \(y^{2}\).
06
Combine the simplified terms for the answer.
Combine the simplified terms: \(5 \cdot x^{\frac{3}{2}} \cdot y^{2}\).
So, \(\left(25 x^{3} y^{4}\right)^{1 / 2} = 5x^{\frac{3}{2}}y^2\).
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Power to a Power Rule
When you see an expression where a base with an exponent is raised to another power, like \((a^m)^n\), you apply the "power to a power" rule. This rule states that you multiply the exponents, resulting in \(a^{m \cdot n}\). This concept is crucial when simplifying exponential expressions, especially when dealing with nested exponents.
For example, consider \((x^9)^{\frac{1}{3}}\). According to the power to a power rule, multiply 9 and \(\frac{1}{3}\):
For example, consider \((x^9)^{\frac{1}{3}}\). According to the power to a power rule, multiply 9 and \(\frac{1}{3}\):
- \(x^{9 \cdot \frac{1}{3}} = x^3\).
Cube Root
The cube root of a number is a value that, when multiplied by itself three times, gives the original number. The cube root is represented by the radical symbol with a small 3 above it, like \(\sqrt[3]{a}\). Finding the cube root is common in algebra simplification problems.
When you encounter an expression like \(64^{\frac{1}{3}}\), you're essentially finding the cube root of 64. Which means:
When you encounter an expression like \(64^{\frac{1}{3}}\), you're essentially finding the cube root of 64. Which means:
- \(\sqrt[3]{64} = 4\) because \(4 \times 4 \times 4 = 64\).
Square Root
Square roots are quite similar to cube roots but simpler since they deal with multiplying a number by itself just two times. The square root of a number \(a\) is written as \(\sqrt{a}\). Finding the square root is used commonly in solving equations and simplifying expressions.
Take for example, the expression \(25^{\frac{1}{2}}\). Here, you are tasked with finding the square root of 25:
Take for example, the expression \(25^{\frac{1}{2}}\). Here, you are tasked with finding the square root of 25:
- \(\sqrt{25} = 5\) because \(5 \times 5 = 25\).
Exponents Simplification
Simplifying expressions with exponents involves a variety of operations including breaking down powers, multiplying bases, and utilizing both square and cube roots. When taking expression like \((x^3)^{\frac{1}{2}}\) or \((y^4)^{\frac{1}{2}}\), you simply apply the power to a power rule:
- For \((x^3)^{\frac{1}{2}}\), it becomes \(x^{3 \cdot \frac{1}{2}} = x^{\frac{3}{2}}\).
- For \((y^4)^{\frac{1}{2}}\), it simplifies to \(y^{4 \cdot \frac{1}{2}} = y^2\).