What exactly do you want to solve? 
The Algebrator solved the equation you typed in for variable 'R'.
You can select the variable that you want to have the equation solved for.
After you click on 'Solve' you are asked weather to solve for 'K', 'R', 'c' or 'r':

After you select the variable you need to click on 'Solve' button to get the solution.

For example if you select to solve for 'K':

You will get the following solution: