Two coils have a combined resistance of 9`Omega` when connected in series and 2`Omega` when connected in parallel. Find the resistance of each coil.

Explanation

Data supplied,
`R_(1)+R_(2)=9 Omega "_________(1)", (R_(1)R_(2))/(R_(1)+R_(2) )=2Omega"__________(2)"`
`(1)and (2) rArrR_(1)R_(2)=2(R_(1)+R_(2))=2xx9=18`
`(R_(1)-R_(2))^(2)=(R_(1)+R_(2))^(2)-4R_(1)R_(2)=9^(2)-4xx18=9`
`R_(1)-R_(2)=3Omega"____________"(3)`
solving (1)&(3),`R_(1)=6 Omega and" " R_(2)=3Omega`