estimate the aqueous solubility, in milligrams per liter of AgBr(s) at 160 degrees C

Look up Ksp for AgBr at 160C.

AgBr(s) ==> Ag^+ + Br^-

Set up an ICE chart, substitute into the Ksp expression and solvr for Ag^+ = Br^-
Ksp = (Ag^+)(Br^-)