for 15, you need a portal next to the little wall, then use the ledge to gain speed and jump through another portal on the ground, which will launch you high enough to land on the glass wall, then shoot another portal on the small platform next to the blue stuff, and jump through the portal up top which will launch you high enough to land in the blue area, timing needed, then jump across gap
 "Max Mesiria Chp1 RPG"){kind=icon}
 "Greyhound Racer Rush"){kind=icon}
 "Shoot The Targets"){kind=icon}
 "Portal: The Flash Version"){kind=icon}
 "Mass Attack"){kind=icon}