Step-by-step explanation: cause of that rule that says there is only one output for every input also for graphs you can use see if there are two points on a line then its not a function that's why D isn't cause there are two on X axis (2,-1) and (2,1) :))
Supplementary angles sum up to 180°, suppose the supplement of 161° is x. Then 161+x=180 solving for x we subtract 161 from both sides 161-161+x=180-161 x=19 thus the supplement is 19°
