To determine the correct equation corresponding to the measures of the nonadjacent angles that are complementary, we start with the given angle measures:
- One angle measures \( 3x \) degrees.
- The other angle measures \( 4x + 1 \) degrees.
Since the angles are complementary, their measures add up to 90 degrees. Therefore, we can set up the equation as follows:
\[ 3x + (4x + 1) = 90 \]
Now, we simplify the left-hand side:
\[ 3x + 4x + 1 = 90 \] \[ 7x + 1 = 90 \]
Thus, the simplified equation corresponding to the measures of the angles is:
\[ (7x + 1) = 90 \]
The correct choice is: (7x + 1) = 90.