hello i think im posting in wrong forum for that im sorry but recently i started my A level's and one of my choices was further maths. lately i havent been able to grasp a few things in class. for example

given that "m" is a 2x2 matix

Show that "m squared" = m + I

Show that "m^4" - 3m = 2I

wondering if anyone could help i just can't grasp on how to do this atm..all help will be very much appreciated thankyou.