Question

Which of the following is not irrational? a) (2 – √3)2 b ) (√2 + √3)2 (c) (√2 -√3)(√2 + √3) (d) 27√7
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Answer 1

Answer:

C is the correct option.

Step-by-step explanation:

(√2-√3)(√2+√3)

=(√2)²-(√3)²

as (a-b)(a+b)=a²-b²

=2-3

=-1

Answer 2

Answer:

(√2 -√3)(√2 + √3)

It is the correct answer

Step

[a-b] [a+b] = [a2] - [b2]

(√2 -√3)(√2 + √3) = [√2]2  - [√3]2

                              = 2 - 3

                              = -1