Guild Wars 2

Hi evryone, i have a stupid question, how can i increase the agony recistence for the amulet and rings?,
i mean, actually im at lvl 20 in fractal of the mist, i have equiped 1 amulet and 1 ring each one with +5 agony recistence, this have works great until lvl 19, but now i die at evry boss,
i have tryed to search on the web for how increase it but actually i dont understand how can i do.

You can either infuse the rings or get additional ascended items such as the accessories, back items, weapons and armor.