Deriving Chem Beer's Law's Equation

Question

By comparing the absorbance of each trial solution, Aeq, to the absorbance of the standard solution, Astd, [FeNCS2+]eq can be determined. Two Beer’s Law equations can be written, one for the trial (Aeq = ε[FeNCS2+]eql), one for the standard (Astd = ε[FeNCS2+]stdl).

Set these two equations equal to each other to derive equation (2).

Note : the "l" is a special symbol as well
The derived equation looks like this : [FeNCS2+]eq = Aeq / Astd *[FeNCS2+]std

I'm having trouble deriving it myself? Any tips or help would greatly be appreciated!

Answer 1

The hint tells you how to do it. Set the two equations equal to each other and solve for [FeNCS2+]eq.

Answer 2

I don't understand how its Aeq / Astd * [FeNCS2+]std

What am I setting equal exactly?
ε[FeNCS2+]eql)/Aeq = ε[FeNCS2+]stdl/Astd ?

Answer 3

solve for the epsilon and then plug them in.