10. Prove the following properties of Boolean algebras. Give a reason for each step. a. (x+y)+(y x?)=x+y

b. (y+x)#(z+y)+x#z#(z+z?)=y+x#z

c. (y?#x)+x+(y+x)#y?=x+(y?#x) ##

d. (x+y?) z=#3(x?+z?) (y+z?)4?

e. (x#y)+(x?#z)+(x?#y#z?)=y+(x?#z)