<prompt> Nambari halisi a,b,c, na d zinatoshelezaa2 b2 c2 1 d sqrta b c - d.Tafuta d.  <response>: Acha x sqrta b c - d. Kisha x2 a b c - d, hivyo d a b c - x2, na tunaweza andikaa2 b2 c2 1 a b c - x2 x.Kishaa2 - a b2 - b c2 - c x2 - x 1 0.Kukamilisha mraba katika a, b, c, na x, tunapatakushoto a - frac12 kulia2 kushoto b - frac12 kulia2 kushoto c - frac1 2 kulia2 kushoto x - frac12 kulia2 0.Kwa hivyo, a b c x frac12 , hivyod a b c - x2 frac12 frac12 frac12 - frac14 frac54. 