Declension table of ?samarthatva

Neuter	Singular	Dual	Plural
Nominative	samarthatvam	samarthatve	samarthatvāni
Vocative	samarthatva	samarthatve	samarthatvāni
Accusative	samarthatvam	samarthatve	samarthatvāni
Instrumental	samarthatvena	samarthatvābhyām	samarthatvaiḥ
Dative	samarthatvāya	samarthatvābhyām	samarthatvebhyaḥ
Ablative	samarthatvāt	samarthatvābhyām	samarthatvebhyaḥ
Genitive	samarthatvasya	samarthatvayoḥ	samarthatvānām
Locative	samarthatve	samarthatvayoḥ	samarthatveṣu

Compound samarthatva -

Adverb -samarthatvam -samarthatvāt