To solve for \( x \), we start by recognizing that vertical angles are equal. Therefore, we have:
\[ m\angle 1 = m\angle 3 \]
From the problem, we know:
\[ m\angle 1 = (4x + 26)^\circ \] \[ m\angle 3 = 98^\circ \]
Setting these two expressions equal to each other gives us the equation:
\[ 4x + 26 = 98 \]
Now, we can solve for \( x \).
- Subtract 26 from both sides:
\[ 4x = 98 - 26 \]
\[ 4x = 72 \]
- Now, divide both sides by 4:
\[ x = \frac{72}{4} \]
\[ x = 18 \]
Thus, the value of \( x \) is
\[ \boxed{18} \]