Since, zz(z2+z2)=350 ⇒2(x2+y2)(x2−y2)=350 ⇒(x2+y2)(x2−y2)=175 Since, x,y∈I, the only possible case, which gives integral solution, is x2+y2=25 .......(i) x2−y2=7....... (ii) From Eqs. (i) and (ii), we get x2=16,y2=9⇒x=±4,y=±3 ∴ Area of rectangle =8×6=48