f)
=(39/1000):{(1/20)[(231/100) :(77/1000)]}-4,617=
=(39/1000):{(1/20)[(231/100)x(1000/77)]}-4,617=
=(39/1000):[(1/20)(3x10)]-4,617=
=(39/1000):(3/2)-4,617=
=(39/1000)x(2/3)-4,617=
=26/1000 +4617/1000=
=4643/1000=4,643
a)
=(-2/3)x(2008/2013)-(2/3)x(5/2013)=
=factor comun (-2/3)(1/2013)=
=(-2/3)(1/2013)(2008+5)=
=(-2/3)(1/2013)x2013=
=-2/3