Answer:
x = 41
Explanation:
The angles shown are supplementary
Supplementary angles add up to equal 180
This means that x + 16 + 123 = 180
x + 16 + 123 = 180
Solve for x
Combine like terms ( add 16 and 123 )
x + 139 = 180
Subtract 139 from both sides
x = 41