Classify the following numbers as rational or irrational: (i) 2 - √5 (ii) (3 +√23) - √23 (iii) 2√7/7√7
Classify the following numbers as rational or irrational:
(i) 2 - √5
(ii) (3 +√23) - √23
(iii) 2√7/7√7
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(i) 2 - √5
We kno that √5 = 2.236..., which is an irrational number
2 - √5 = 2 - 2.236..
= -0.236..., which is also an irrational number.
Therefore, we conclude that 2 - √5 is an irrational number.
(ii) (3 +√23) - √23
(3 +√23) - √23 = 3 +√23 - √23 = 3.
Therefore, we conclude that (3 +√23) - √23 is a rational number
(iii) 2√7/7√7
We can cancel √7 n the numerator and denominator, as √7 is the the common number in numerator as well as denominator, to get
2√7/7√7 = 2/7
Therefore, we conclude that 2√7/7√7 is rational number.
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