Bg 5.4

sankhya-yogau prthag balah
pravadanti na panditah
ekam apy asthitah samyag
ubhayor vindate phalam

Word for word: 
sankhya — analytical study of the material world; yogau — work in devotional service; prthak — different; balah — the less intelligent; pravadanti — say; na — never; panditah — the learned; ekam — in one; api — even; asthitah — being situated; samyak — complete; ubhayoh — of both; vindate — enjoys; phalam — the result.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Only the ignorant speak of devotional service [karma-yoga] as being different from the analytical study of the material world [Sankhya]. Those who are actually learned say that he who applies himself well to one of these paths achieves the results of both.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The aim of the analytical study of the material world is to find the soul of existence. The soul of the material world is Visnu, or the Supersoul. Devotional service to the Lord entails service to the Supersoul. One process is to find the root of the tree, and the other is to water the root. The real student of Sankhya philosophy finds the root of the material world, Visnu, and then, in perfect knowledge, engages himself in the service of the Lord. Therefore, in essence, there is no difference between the two because the aim of both is Visnu. Those who do not know the ultimate end say that the purposes of Sankhya and karma-yoga are not the same, but one who is learned knows the unifying aim in these different processes.