You should upgrade or use an alternative browser. A number means an arbitrary variable, let's call it "x".
4 times a number is 4x.
Plus 9 means we add:
4x + 9
ncG1vJloZrCvp2O6osDHnJylnZKntrXFjZympmeTpLquwc2iq7JnpJ2%2Fpq3DrGZtZaSeuqa%2FjJpkp62dl7Kzec%2BlrKxlaWN%2Fc3%2BO