Since 1 US Dollar is equal to 78.000625 Russian Rubles, we could say that n United States Dollars are equal to 78.000625 times n Russian Rubles. In other words, we could use the following formula:
Russian Rubles = United States Dollars x 78.000625
For example, let's say that we want to convert 2.0 United States Dollars to Russian Rubles. Then, we just replace United States Dollars in the abovementioned formula with 2.0:
Russian Rubles = 2.0 x 78.000625
That is, 2.0 United States Dollars are equal to 156.00125 Russian Rubles.