I can not understand the solution for this question, could you explain it for me please.

4. Calculating Option Values (LO2) The price of Newgen Corp. stock will be either $53 or $84 at the end of the year. Call options are available with one year to expiration. T-bills currently yield 6%. a. Suppose the current price of Newgen stock is $85. What is the value of the call option if the exercise price is $75 per share? (LO2) a. Value of the call equals stock price less present value of exercise price." 85 = [(84-53)/(9-0)]Co+53/1.064 Co=$10.16