\[\boxed{\mathbf{443}.}\]
\[1)\ 11,64 + x = 30\]
\[x = 30 - 11,64\]
\[x = 18,36.\]
\[2)\ 4,21 - x = 4,178\]
\[x = 4,21 - 4,178\]
\[x = 0,032.\]
\[3)\ x - 1,745 = 1,255\]
\[x = 1,255 + 1,745\]
\[x = 3.\]