In the same experiment, we found the absorbance of three unknown solutions at 635 nm. How do i use this information to find Molarity?

i believe it is M=moles/L

but i don't have the moles or L

You use the absorbance and a known concn or the constant value.

A = abc where A is absorbance, a is a constant, b is the path length, and c is the concn Iif c is in moles/L, then a is called the molar absorptivity constant).