Hi does anyone know the answer

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

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