Question

Find the sum of 3, square root of, 5, end square root3
5

and 4, square root of, 8, end square root4
8

in simplest form. Also, determine whether the result is rational or irrational and explain your answer.
Answer
Attempt 1 out of 5

Result:


The result is
because it
be written as the ratio of two integers and its decimal expansion
terminate or repeat.

Answers

Answered by GPT-4o mini
To find the sum of \( 3\sqrt{5} \) and \( 4\sqrt{8} \), let's first simplify \( 4\sqrt{8} \).

Since \( \sqrt{8} = \sqrt{4 \times 2} = \sqrt{4} \cdot \sqrt{2} = 2\sqrt{2} \), we can rewrite \( 4\sqrt{8} \) as:

\[
4\sqrt{8} = 4(2\sqrt{2}) = 8\sqrt{2}
\]

Next, we sum \( 3\sqrt{5} \) and \( 8\sqrt{2} \):

\[
3\sqrt{5} + 8\sqrt{2}
\]

Now we cannot combine \( 3\sqrt{5} \) and \( 8\sqrt{2} \) further because they are not like terms.

Thus, the sum in simplest form is:

\[
3\sqrt{5} + 8\sqrt{2}
\]

Now, to determine whether this result is rational or irrational, we need to analyze each term:
- The number \( \sqrt{5} \) is an irrational number.
- The number \( \sqrt{2} \) is also an irrational number.

When we multiply a rational number (like \( 3 \) or \( 8 \)) by an irrational number, the result is still irrational. Therefore:
- \( 3\sqrt{5} \) is irrational.
- \( 8\sqrt{2} \) is also irrational.

The sum of two irrational numbers can be rational or irrational. In this case, \( 3\sqrt{5} + 8\sqrt{2} \) cannot be expressed as a ratio of two integers, which implies that the sum is irrational.

### Final answer:
The result is \( 3\sqrt{5} + 8\sqrt{2} \) because it cannot be written as the ratio of two integers and its decimal expansion does not terminate or repeat. Thus, the result is **irrational**.

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