Since ∠1 and ∠3 are a vertical pair, they are congruent angles and have equal measures.
Therefore, 4x + 26 = 98.
Subtracting 26 from both sides of the equation, we get:
4x = 98 - 26.
Simplifying the right side, we have:
4x = 72.
To solve for x, divide both sides of the equation by 4:
x = 72/4.
Simplifying the right side, we get:
x = 18.
Therefore, the value of x is 18.