Explanation:
The age of the universe is 13.8 billion years.
We know that,
1 billion years = 10⁹ years
So,
[tex]13.8\ \text{billion years}=13.8\times 10^9\ \text{years}[/tex]
We need to convert the age of the universe to the scientific notation.
Since, [tex]1\ \text{year}=3.154\times 10^7\ s[/tex]
So,
[tex]13.8\times 10^9\ \text{years}=13.8\times 10^9\times 3.154 \times 10^7\\\\=4.35\times 10^{17}\ s[/tex]
So, the age of the universe is [tex]4.35\times 10^{17}\ s[/tex].