=5/9×9/5+5/9× 18

= 1+ 10

= 1 1

5/9X5/6+4/9÷6/5

= 5/9×5/6+4/9×5/6

=(5/9+4/9)×5/6

= 1×5/6

=5/6

13/ 14- 15/28÷5/8

= 13/ 14-6/7

= 1/ 14

4÷4/5-4/5÷4

=5- 1/5

=4 4/5

(5/6-3/4)÷3/8

= 1/ 12×8/3

=2/9

7/ 1 1÷[2/5-( 1-7/ 10)]

=7/ 1 1÷[2/5-3/ 10)]

=7/ 1 1÷ 1/ 10

=70/ 1 1