Since ∠1 and ∠3 are a vertical pair, their measures are equal. Thus, we can set the equations equal to each other:
\[ m∠1 = m∠3 \]
Substituting the given expressions:
\[ 4x + 26 = 98 \]
To solve for \(x\), first subtract 26 from both sides:
\[ 4x = 98 - 26 \] \[ 4x = 72 \]
Now, divide both sides by 4:
\[ x = \frac{72}{4} = 18 \]
So, the value of \(x\) is \( \boxed{18} \).