Step-by-step explanation:
BFE + BFG = 180 => Sum of angles on a
straight line
BFE = 180 - BFG
= 180 - 147
= 33
BED + BEF = 180 => Sum of angles on a
straight line
BEF = 180 - BED
= 180 - 4x
EBF + BFE + BEF = 180 => Sum of angles in a
triangle
x + 33 + (180 - 4x) = 180
x + 33 + 180 - 4x = 180
x - 4x + 33 + 180 = 180
-3x + 213 = 180
-3x = 180 - 213
-3x = -33
x = -33/-3 = 11
x = 11
