Boolean Algebra 31. Why are NAND and NOR considered universal gates? 32. Simplify following Boolean expressions: a) xy+xz+yz b) xyz+xyz+xz c) y+(xy) d) (xy)(x+y)(y+y) e) (A+B)(A+C) f) ABC+ABC+AC g) (X+Y)(Y+Y) h) x+xy i) x+xy j) a+ab+ac+acd k) xy+xy+xy 1) x+xy+xz+xyz m) ab+bc+ab+c