What is the effect on the graph of f(x) if it is changed to f(x) + 7 and f(x + 7)? linear, quadratic and exponential

When using the linear combination metho e linear combination method to solve a system of linear equations, the four options are:

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

What percent of 18 is 24? and plz explain thx.