To simplify the expression \(20 + 16a - 6a\), you combine like terms.
The terms involving \(a\) are \(16a\) and \(-6a\):
\[ 16a - 6a = 10a \]
Now, substituting back into the expression, we have:
\[ 20 + 10a \]
So the simplified expression is:
\[ 20 + 10a \]