Question

M08.B-E.1.1.2

Lessons 1 and 2



Which expression is rational?

Group of answer choices

4.121221222...

square root of 36

square root of 21

1.192744502...

Answer 1

To determine which expression is rational, we need to identify if the numbers can be expressed as a fraction of two integers.

1. **4.121221222...** - This is a repeating decimal, which means it can be expressed as a fraction. Therefore, it is rational.

2. **Square root of 36** - This equals 6, which is an integer. All integers are rational numbers because they can be expressed as a fraction (6/1). Thus, this is rational.

3. **Square root of 21** - This is an irrational number because it cannot be expressed as a fraction of two integers. Therefore, it is not rational.

4. **1.192744502...** - This is a non-repeating decimal, which means it cannot be expressed as a fraction of two integers. Therefore, it is not rational.

Based on this analysis, the expressions that are rational are:

- **Square root of 36** (6)
- **4.121221222...**

If you are looking for just one example, **square root of 36** is definitely rational and straightforward because it equals a whole number (6).