Because they form a straight line,
m∠GFC + m∠GFB = 180°
m∠GFC = 180° – m∠GFB
m∠GFC = 180° – 140°
m∠GFC = 40°
Because the sum of interior angles in △CGF is 180°,
m∠GFC + m∠GCF + m∠CGF = 180°
40° + 59° + 3y° = 180°
3y° = 81°
y = 27
Because the sum of interior angles in △CGE is 180°,
m∠GEC + m∠GCE + m∠CGE = 180°
x° + 59° + 2y° = 180°
x° + 59° + 2(27)° = 180°
x° + 59° + 54° = 180°
x° = 180° – 59° – 54°
x° = 67°