Question

Please help me...If A= {x:x=3n, n€Z} and B= {x:x=4n,n€Z} then find A intersection B.

Answer 1

Answer:

A intersection B = { ±12, ±24, ± 34.....}

Step-by-step explanation:

A= { x:x= 3n, n€ Z}

A= {±3,±6,±9,±12,±15,..........}

B= {x:x=4n,n€Z}

B= {±4,±8,±12,±16,±20,..........}

A intersection B = {±12,±24,±34.........}

Answer 2

Given:

A= {x:x=3n, n€Z}

B= {x:x=4n,n€Z}

Z represents the integers.

to find :

find A intersection B.

Solution:

set A represents the set of integers which are multiple of 3.

x is given by 3n , n= 1,2,3,4,5,6,7,8,910,11,12.........

so x = 3,6,9,12,15,18,21,24,27,30,33,36   so x is a multiple of 3.

A = { 3,6,9,12,15,18,21,24,27,30,33,36...........}

set A represents the set of integers which are multiple of 4.

x is given by 4n , n= 1,2,3,4,5,6,7,8,9.........

so x = 4,8,12,16,20,24,28,32,36

B= {4,8,12,16,20,24,28,32,36.................}

So intersection of A and B will be common numbers between A and B.

common numbers between A and B are 12,24,36....................

So it is clearly evident that the common numbers are the multiples of 12.

So A ∩ B = { 12,24,36,48....................}

A ∩ B = {x:x=12n, n€Z}