How to get 100 using four 9's and sum of the symbols like '+' , '-' , '*' etc.?
Get 100 using four 9's and some of the symbols like +,-,*,/
How to join two chemical to derive its formula like for hydrogenchloride we use a symbol like HCl how is that possible using their symbol ? I know to create but how to use valency and where to use it I don’t know.