Question

From the given numbers which is an irrational number?
(3+√23),
2-√5,
√25,
(2√7)/(7√7)
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Answer 1

(3+√23) and (2-√5) both are irrational numbers .

Step-by-step explanation:

√23 is an irrational number..so 3+√23 is also an irrational number.

√5 is an irrational number...so 2-√5 is also an irrational number.

√25 gives 5 which is a rational number.

(2√7)(7√7) gives 98 which is a rational number.

Answer 2

Given:

The numbers

1. 3+√23
2. 2-√5
3. √25
4. (2√7)(7√7)

To find:

The irrational numbers among the given numbers

Calculation:

3 is a rational number and √23 is an irrational number. As the sum of rational number and irrational number is irrational, 3+√23 will be an irrational number

2 is a rational number and √5 ia an irrational number. As the difference of rational and irrational number is irrational, 2-√5 will be an irrational number

√25 = 5

5 is a rational number. Therefore √25 is a rational number

2√7×7√7 = 98

98 is a rational number. Therefore (2√7)(7√7) will be a rational number

Final answer:

The irrational numbers are 3+√23, 2-√5