Пошаговое объяснение:
21/30+3/30-8/30=(21+3-8)/30=16/30
61/200-(35/200-19/200)=
=61/200-(35-19)/200=61/200-16/200=
=(61-16)/200=45/200
21/65-16/65+13/65=(21-16+13)/65=
=18/65
21/30-(1/30+9/30)=21/30-(1+9)/30=
=21/30-10/30=11/30
17/19-(5/19+2/19)=17/19-(5+2)/19=
=17/19-7/19=10/19
3/10+5/10-7/10=(3+5-7)/10=1/10
Пошаговое объяснение:
21/30+3/30-8/30=(21+3-8)/30=16/30
61/200-(35/200-19/200)=
=61/200-(35-19)/200=61/200-16/200=
=(61-16)/200=45/200
21/65-16/65+13/65=(21-16+13)/65=
=18/65
21/30-(1/30+9/30)=21/30-(1+9)/30=
=21/30-10/30=11/30
17/19-(5/19+2/19)=17/19-(5+2)/19=
=17/19-7/19=10/19
3/10+5/10-7/10=(3+5-7)/10=1/10