Please help with this one question

g(x)=8x+2

100 points, hi, i’m not sure how to get the equation from the graph and table.

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?

The value of the expression 16-^3/4 8 1/8 -6 6 1/40 1/64