Question 346545
Let s = selling price


s = 2c + 125


We need to find c when s = 325.


325 = 2c + 125


325 - 125 = 2c


200 = 2c


200/2 = c


100 = c


The cost is $100.


NOTE: I decided to use the letters s and c for this linear equation but you can use any letters.