MOT advisories

Had an MOT done on my 2007 Peugeot 107 1.0L on 72k miles and had these advisories, am I meant to get them repaired and how much would they typically cost?

Nearside Rear Brake pipe corroded, covered in grease or other material (1.1.11 (c)) Offside Rear Brake pipe corroded, covered in grease or other material (1.1.11 (c)) Nearside Rear Suspension arm pin or bush worn but not resulting in excessive movement trailing arm (5.3.4 (a) (i)) Offside Rear Suspension arm pin or bush worn but not resulting in excessive movement trailing arm (5.3.4 (a) (i)) Nearside Front Suspension arm pin or bush worn but not resulting in excessive movement (5.3.4 (a) (i)) Offside Front Suspension arm pin or bush worn but not resulting in excessive movement (5.3.4 (a) (i))