What is equivalent to this statement: 4 is 80% of x

Aformual for 8 bottles of window cleaner calls for 6 cups of rubbing to customers alcohol 2 1/4 gallons of water and 1 1/2 cups of ammonia alcohol would the forula call if a factory made 1,280 bottles for stores to sell to customers

Percent increase and decrease. original number: 45 new number: 18

F(x)=5/6x+3 which of the following is true