b) -5/ 12 : (1/ 11 - 5/22) + -5/ 12 : ( 1/15 - 2/3)

b) −512:111−522+−512:115−23  = −512:222−522+−512:115−1015 =   −512:−322+−512:−915

= =−512.−223+−512.−159= −512.−223+−159=−512.−223+−53=−512.−273=−512.−9=154