<span>1) (980+930-890):2=510р у Ивана
</span><span>2)980-510=470р у Петра </span>
<span>3)890-470=420р у Никиты</span>
а) 9_5/19 - 7_7/19 + 4_15/19=
= 8 24/19 - 7_7/19 + 4_15/19=
=1 17/19+4 15/19=5 32/19=6 13/19
б) 5_3/28 + 6_25/28 - 7_9/28=
=11 9/28-7 9/29=4
в) 14_5/29 - (5_21/29 + 4_9/29)=
=14_5/29 -9 30/29=14_5/29 -10 1/29=
=4 4/29