=25/8÷(53/ 12-85/24)×4/7+(55/ 18-3 1/ 12)×27/ 17

=25/8÷( 106/24-85/24)×4/7+( 1 10/36-93/36)×27/ 17

=25/8÷7/8×4/7+3/4×27/ 17

=25/8÷ 1/2+8 1/68

=25/8÷34/68+8 1/68

=25/8÷ 1 15/68

=25/8×68/ 1 15

=85/46

(-6.5)-(-4 and 1/4))+8.75-(+3 and 1/2)+5.

=-6.5+4.25+8.75-3.5+5

=-(6.5+3.5)+(4.25+8.75)+5

=-3+ 13+5

= 15

(| 3/4 |- 1 and 1/4|)-|-5/2-(-7/4)|

=(3/4- 1 and 1/4)-|-5/2+7/4|

=(3/4- 1 and 1/4)-|- 10/4+7/4|

=3/4- 1 and 1/4-3/4

=3/4-3/4- 1 and 1/4

=- 1 and 1/4