solve for x

To solve for \( x \) in the equation \(-4x + 1 = 21\), follow these steps:

1. Subtract \( 1 \) from both sides:

\[
-4x + 1 - 1 = 21 - 1
\]

This simplifies to:

\[
-4x = 20
\]

2. Next, divide both sides by \(-4\):

\[
x = \frac{20}{-4}
\]

This simplifies to:

\[
x = -5
\]

So the solution is:

\[
x = -5
\]