Q3: (10 pt.)
Simplify each of the following expressions using Boolean algebra.
(a) f(a, b, c, d) = b + bcd + bcd + ab + ab + bc
(b) f(x, y, z, w, k) = (xy + z + w)(z+w) (z+w+k)
(c) f(a, b, c) = bc(c + ca) + (ā + c)(ab + āc)
(d) f (a, b, c, d) = (a + c + d)(b + c)(a + b + d)(b+c)(b+c+d)