Question

Find the smallest set a such that a union {1,2}={1,2,3,5,9}

Answer 1

Answer:

Set A = { 3 , 5 , 9 }

Step-by-step explanation:

A u { 1 , 2 } = { 1 , 2 , 3 , 5 , 9 }

So ,

Set A can be either { 3 , 5 , 9 } or { 1 , 2 , 3 , 5 , 9 }

But it is given that X is the smallest ,

So ,

X = { 3 , 5 , 9 }

Answer 2

Given :

A U {1,2} = {1,2,3,5,9}

To find :

set A

Step-by-step explanation:

Let B = {1,2}

C = {1,2,3,5,9}

The set A must be the union of C - B or C + B.

Hence ,

A =  {3,5,9} or {1,2,3,5,9}

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SPJ2