5(a-b), if a= -4, b =-2

What are “like terms”? why can we only add like terms?

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

Answer asap evaluate 4-0.25g+0.5h4−0.25g+0.5h when g=10g=10 and h=5h=5.