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Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)

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?

Simplify (1/2)4th power a. (1/16) b.(1/8) c.(1/4)