Answer:
x = 12
Explanation:
m<BCF and m<CFE are same-side interior angles.
Same-side interior angles are supplementary. This implies that:
m<CFE + m<BCF = 180°
where,
m<CFE = 11x°
m<BCF = 4x°
Plug in the values
11x + 4x = 180
15x = 180
x = 180/15
x = 12