b: \(\Leftrightarrow\left[{}\begin{matrix}x+7=11\\x+7=-11\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-18\end{matrix}\right.\)
\(\left(19x+13^2\right):5=49\\ \left(19x+169\right):5=49\\ 19x+169=49.5\\ 19x+169=245\\ 19x=245-169\\ 19x=76\\ x=76:19\\ x=4\)