Please help I’ll give you brain lists points and likes

If eh = hg and hg=16, find the diameter of k

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

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?