1)1)2 5/9 - 1 20/21=
=2 35/63- 1 60/63=38/63
2)38/63 ÷ 1 8/49=
=38/63 × 49/57=14/27
3)1 8/9 ÷ 6=
=17/9 × 1/6=17/54
4)14/27 + 17/54=
=28/54 + 17/54=45/54=5/6
2)1)1 17/18 × 1 13/14=
= 35/18 × 27/14=3 3/4
2)2 5/8 ÷ 1 19/20=
=21/8 × 20/39=1 9/26
3)3 3/4 - 1 9/26= 2 21/52
4)2 25/78 - 1 1/26=
=2 25/78 - 1 3/78=1 24/78=1 4/13
5)2 21/52 - 1 4/13= 2 21/52 - 1 16/52=
=1 5/52