The correct option is A 9,6 or 9,−6
Wetakethebiggernumberasx&thesmalleroneasy.Then,bythefirstcondition,x2−y2=45..........(i)andy2=4x........(ii)Substitutingy2=4xin(ii)wegetx2−4x−45=0⟹(x+5)(x−9)=0⟹x=−5,9.Werejectx=−5becausesubstitutingthisvalueofxin(ii)wehavey2=4×(−5)=−20i.eyisnotarealnumber.∴weacceptx=9.Substitutingthisvalueofxin(ii)wehavey2=4×9⟹y=±6.∴(x,y)=(9,6)or(9,−6).Ans−OptionA.