Răspuns:
(1/6+7/9)×18/17=
=17/18×18/17=
=1
(5/6+7/8)×18/41+1/4=
=41/24×18/41+1/4=
=1/4×3+1/4=
=3/4+1/4=
=4/4=
=1
(5/12-3/18)×4=
=1/4×4=
=4/4=
=1
(11/45-1/30)×18/19=
=19/90×18/19=
=1/90×18=
=1/5
(11/12-7/15)×10/9+1/2=
=9/20×10/9+1/2=
=1/20×10+1/2=
=1/2+1/2=
=2/2=
=1
Sper că te-am ajutat!