Question

A= (x:x is a common factor of 12 and 18}<br />B=(x:x = n²-n where nEN, n<5 ) hen<br />find h(AUB} and CANB).​

Answer 1

Answer:

set A { 1 2 3 6 }

to form se B let n be 1, 2, 3 ,4 (as n<5 and natural numbers N starts from 1 )

as x = n^2 - n, put all the four values of n and get corresponding values of x

therefore values of x are 1^2 - 1 = 0, 2^2 - 2 = 2,

3^2 - 3 = 6 and 4^2 - 4 = 12

set B= { 0 2 6 12 }

A ∪ B = { 0 1 2 3 6 12 }

n (A ∪ B) = 6

2nd part of the question is not clear