To simplify the expression \((5y - 1) + (-27x + 4)\), we can combine like terms:
- Combine the constant terms: \(-1 + 4 = 3\)
- The terms with \(y\) remain as \(5y\).
- The term with \(x\) is \(-27x\).
Putting it all together:
\[ (5y - 1) + (-27x + 4) = 5y - 27x + 3 \]
So the simplified expression is:
\[ 5y - 27x + 3 \]