have been asked to write how i got this equation but i cant put it in words can you help me

Al2 Se3 +6 H2O ==> 2Al (OH)3 +3H2Se

i can do this but like i said putting it into words i just cannot make it coherant

The answer you should give is you found it on the internet. The reaction of aluminum selenide with water yeilds aluminum hydroxide and hydrogen selenide.