b) 5/9 : ( 1/11 - 5/ 22) + 5/9 : ( 1/15 - 2/3) .

b)  59:111−522+59:115−23= 59:222−522+59:115−1015

= 59:−322+59:−915  = 59.22−3+59.15−9  = 59.22−3+15−9

= 59.−223+−53= 59.−273=59.−9=−5