Write out the balanced equation for the reaction that occurs when li and h2o react together. you do not need to make your subscripts smaller; just write them out as regular numbers. for example: h2o.

Li + H2O →  LiOH + H2 

The equation is currently unbalanced, so to balance it out, you have to have the same number of each molecule on each side. It'll look like this: 

2Li + 2H2O → 2LiOH + H2 

Also, in case you want to identify the phases as well, it'll be like this: 

2Li (s) + 2H2O (l) → 2LiOH (aq) + H2 (g)

"s" is solid. 
"l" is liquid. 
"aq" is aquas. 
"g" is gas.