Which of the following can be used to evaluate the series 8 sigma k-1 5(2/3)k-1?

In the field of thermodynamics, rankine is the unit used to measure temperature. one can convert temperature from celsius into rankine using the formula c= r/1.8 - 273, what is the temperature in celcius corresponding to r degrees rankine.

Hi, can anyone show me how to do this problem? 100 points for this. in advance

Suppose y varies directly with x. write a direct variation equation that relates x and y. then find the value of y when x=12 y=7 when x=3