Gnomish
felegra-
verb. to equal
felcha-
verb. to equal
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A verb appearing as G. felegra- or felcha- in the Gnomish Lexicon of the 1910s, based on G. feleg “equal” and glossed “equal (c. dat.)” (GL/34). The “c. dat.” probably means that the thing equaled is in the dative, e.g. “A [is] equal to B”.
Neo-Sindarin: Since I update G. feleg to ᴺS. bíleb “equal”, I would update this verb ᴺS. bilebra- “to be equal [to]”. I would further assume it requires a dative marker an as in A bilebra an B.