Is equivalent to , please help and show the work

How do you use the additive inverse to evaluate an expression that uses subtraction in a full sentence

In a certain pentagon, the interior angles are a, b,c, d,e where a, b,c, d,e are integers strictly less than 180. ("strictly less than 180" means they are "less than and not equal to" 180.) if the median of the interior angles is 61 and there is only one mode, then what are the degree measures of all five angles?

Your friend uses c=50p to find the total cost, c, for the people, p, entering a local amusement park what is the unit rate and what does it represent in the context of the situation?