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Simplify each square root expression. Describe the simplified form of the expression as rational or irrational. In your final answer, include all of your work.
√121
√48
Simplify each cube root expression. Describe the simplified form of the expression as rational or irrational. In your final answer, include all of your work.
3√81
3√-64

User Ianks
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2 Answers

5 votes

1. √121:

To simplify this expression, we need to find the square root of 121. The square root of 121 is 11, since 11 * 11 = 121. Therefore, the simplified form of √121 is 11.

Since 11 is a whole number, it is considered a rational number.

2. √48:

To simplify this expression, we need to find the square root of 48. We can simplify it by factoring 48 into its prime factors: 48 = 2 * 2 * 2 * 2 * 3.

Taking out pairs of identical prime factors, we get √48 = √(2 * 2 * 2 * 2 * 3) = 2 * 2 * √3 = 4√3.

The simplified form of √48 is 4√3.

Since 4√3 cannot be expressed as a fraction, it is considered an irrational number.

Now let's simplify each cube root expression and describe the simplified form as rational or irrational.

3. 3√81:

To simplify this expression, we need to find the cube root of 81. The cube root of 81 is 4, since 4 * 4 * 4 = 81. Therefore, the simplified form of 3√81 is 4.

Since 4 is a whole number, it is considered a rational number.

4. 3√-64:

To simplify this expression, we need to find the cube root of -64. The cube root of -64 is -4, since -4 * -4 * -4 = -64. Therefore, the simplified form of 3√-64 is -4.

Since -4 is a whole number, it is considered a rational number.

In summary:

- √121 simplifies to 11, which is a rational number.

- √48 simplifies to 4√3, which is an irrational number.

- 3√81 simplifies to 4, which is a rational number.

- 3√-64 simplifies to -4, which is a rational number.

User Ron Badur
by
7.7k points
0 votes

Answer:

Sure, I'd be happy to help you with these problems!

Simplifying square root expressions:

√121 = 11

The square root of 121 is a rational number because it can be expressed as a ratio of two integers (11/1).

√48 = √(16*3) = √16 * √3 = 4√3

The square root of 48 is an irrational number because it cannot be expressed as a ratio of two integers.

Simplifying cube root expressions:

3√81 = 3√(3^4) = 33 = 9

The cube root of 81 is a rational number because it can be expressed as a ratio of two integers (9/1).

3√(-64) = 3√(-444) = 34√(-4) = 12i√2

The cube root of -64 is an irrational number because it cannot be expressed as a ratio of two integers. However, it can be expressed as a product of a rational number (4) and an imaginary number (i√2), where i is the imaginary unit (i.e., i^2 = -1). Therefore, the simplified form of this expression is an imaginary number.

User Jumhyn
by
8.4k points
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