Simplify the following expressions in (1) sum of the products and (2) products of sums:

a) x′z′ + y′z′ + yz′ + xy

b) ac′ + b′d + a′cd + abcd

c) (a′ + b′ + d′) (a + b′ + c′) (a′+ b + d′)(b+ c′ + d′)

4. what is the reason for including the following code snippet in the header file animal.h? #ifndef animal_h #define animal_h class animal { public: animal(); animal(double new_area_hunt); void birth(); void hunt(double new_area_hunt); void death(); double get_area_hunt() const; private: double area_hunt; }; #endif