Hi there! :)
[tex]\large\boxed{x = 3}[/tex]
According to the exterior angle theorem, the angle ∠ADC is equal to the sum of ∠C and ∠B. Therefore:
120 = (15 + 5) + (22x + 4)
Combine like terms:
120 = 37x + 9
Subtract 9 from both sides:
111 = 37x
Divide both sides by 37:
x = 3.
