Question

$x$ is a whole number. If the only common factors of $x$ and $x^2$ are $1$ and $x$, then $x$ is ___.

Accepted Answer

D. The common factors of $x$ and $x^2$ are simply all the factors of $x$. If the only factors of $x$ are $1$ and $x$ itself, then by definition $x$ must be a prime number.

Factors of Numbers

Explanation

Practise this under exam conditions