The change, from the predicted data to the actual data, in the average number of downloads of the application for Company A from the day the application was launched to 4 days after the application was launched would decrease by approximately 244 downloads per day.
The change, from the predicted data to the actual data, in the average number of downloads of the application for Company B from the day the application was launched to 4 days after the application was launched would increase by approximately 174 downloads per day.
Based on this information, Company B made a more accurate prediction of the average number of downloads of the application per day.
The domain of an expression is the range of all values for which the expression is defined. Looking at the expression, it will legal everywhere except when a^2 - 5a - 36 is equal to 0. Since that's a quadratic equation, we can use the quadratic formula to find where its value is 0, giving -4 and 9.
Therefore the domain of the expression is, All real numbers except -4 and 9.