Question

If A ⊂ B, then A ∩ B = A ∪ B.

Answer 1

You can illustrate this with a Venn diagram

Answer 2

Answer with Step-by-step explanation:

We are given that two sets A and B

`A\subset B`

We have to prove show that
`A\cap B=A\cup B`

Suppose , x belongs to [tex}A\cap B[/tex]

Then ,
`x\in A,x\in B`

Then,
`x\in (A\cup B)`

If,
`x\in (A\cup B)`

Then,
`x\in A or x\in B`

If
`x\in B` Then, it is not necessary that x belongs to A .

If x belongs to A then

`A\cap B=(A\cup B)`

If x does not belongs to A then

`A\cap B \\eq(A\cup B)`

But, if x belongs to A then x is also belongs to B because A is a subset of B.

Then,
`A\cap B=(A\cup B)`