Exponent of 1

Any number raised to the power of 1 equals itself. So $7^1 = 7$ and $x^1 = x$.

This makes sense: multiplying $x$ by itself once means you have $x$. No multiplication happens, just identity.

This seems obvious, but keep it in mind. When simplifying expressions, $x^1$ often appears and knowing it's just $x$ saves you steps.