What is the value of x in the equation 4x - 10 = 18

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

Atemperature of 1.64◦f corresponds to answer in units of ◦c.

What does independent variable and dependent variable mean in math?