4) a) 3 factor comun:
3(7+1×15+1×13)=
=3×35=
=105
b) 201 factor comun:
201( 327-1×307+1×23)=
=201( 320+23)=
=201× 343=
=68943
c) 707 factor comun
707(1725×1+324×1-321×1)=
=707× 1725=
=1219575
d)33(117+1×15+1×117)=
=33(117+15+117)=
=33(234+15)=
=33×249=
=14157
e)217(427-397-1)=
=217×39=
=8463
Succes!
