To simplify the expression $6n + 2n - 7$, the first step is to combine the like terms, which results in $8n - 7$.

When simplifying algebraic expressions, it is essential to identify and combine like terms first. Like terms are those that share the same variable raised to the same power. In the expression $6n + 2n - 7$, the terms $6n$ and $2n$ are considered like terms since both include the variable $n$ raised to the first power.

To combine these like terms, you simply add their coefficients, which are the numerical parts in front of the variables. In this case, you add $6$ and $2$ together to obtain $8$. Thus, you get $8n$. The term $-7$ is a constant and does not contain a variable, so it remains unchanged.

Consequently, the simplified form of the expression $6n + 2n - 7$ is $8n - 7$. This process of combining like terms streamlines the expression, making it more manageable and easier to work with in subsequent calculations or equations.