The value of x in the diagram is 11
The exterior angle theorem states that the sum of two interior angles is equal to the opposite exterior angles.
This means that if a and b are the interior angles and c is the exterior angle , then
a + b = c
Therefore;
5x + 6x + 2 = 123
collect like terms
11x = 123 - 2
11x = 121
divide both sides by 11
x = 121/11
x = 11
Therefore the value of x is 11