Question

Write this set B={3,9,27,81} in set builder form

Answer 1

Answer:
`B=\{3^x:x\in N, x\leq4\}`

Explanation:

Given set:
`B=\{3,9,27,81\}` which is in a rooster form.

A set-builder form is a mathematical form to representing a set by stating the properties that its elements must satisfy.

In the given set each element is a multiple of 3.

`3=3^1\\9=3^2\\27=3^3\\81=3^4`

So,
`B=\{3^1, 3^2, 3^3, 3^4\}` ,where 1,2,3,4 are natural numbers

The set-builder notation would be :

`B=\{3^x:x\in N, x\leq4\}`, where N is the set of natural numbers.