Please help! Ty how do you do the bottom part ???

Look at this expression. a3b3c a-3b-3c-1 which of the following is the simplest form of the expression above?

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.

Quick translate "x is 12 units from 20" into an equation. what are the values of x being described? if you can answer any of my other questions that'd be great too