A. every set has an element. b. the smallest perfect number is 28. c. is 1.5 an irrational number? d. find the popular approximation of pi. e. can you extract the root of -25?

a) False. b) False. c) No, it's Rational. d) pi=355/113 e) 5i (for Complex Set of Numbers)

Step-by-step explanation:

a) Since there is the empty set. And an axiom assures us the existence of this Set. "There is a set such no element belongs to it"

∅ has no elements.

b) A perfect number is a positive integer equals to the sum of proper divisions

The smallest is 6. Since the proper divisors of 6={3,2,1}. 6=1+2+3

28 is a perfect number, but not the smallest. It is perfect since

28 proper divisors={14,7,4,2} 28=1+2+3+4+5+6+7

c) No, An Irrational number cannot be written as a fraction a/b where "a" and "b" are integers. 1.5 is a rational one, since 3/2 =1.5

d)

=22/7 -1/791= 355/113

e)  Not for Real Numbers, since it is not defined for Real numbers. But for the set of Complex 5i

45

step-by-step explanation:

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