2 1/2= to another mixed number

Asurvey of 45 teens found that they spent an average of 25.6 hours per week in front of a screen (television, computer, tablet, phone, based on the survey’s sample mean, which value could be the population mean? 2.3 hours 27.4 hours 75.3 hours 41.5 hours

How can (square root of 25) ^2 be rewritten?

Which expression is the factorization of x^2+10+21