Chemistry help please !!!

You should be able to use the ICE (Initial, Change, Equilibrium) method for the first example. The initial and equilibrium rows are already given, and the change row would be the difference between the two of them. If you had to work it out from beginning for yourself, start by writing the given initial concentrations in the relevant boxes, and then work out changes in concentrations of Cu²⁺ and Cl^- ions given a change of +x in the concentration of CuCl₄^2- ions. Finally, add each column in change and initial rows to get the values for the equilibrium row.

There's a good worked example in the video below

https://www.youtube.com/watch?v=hCW6z0iXtoY&t=199s

Ah - I see. In the second example, the change in Fe²⁺/Ag⁺ concentration is 0.0439 - 0.05 = -0.0061 mol dm^-3, so the change in Fe³⁺ has to be +0.0061 mol dm^-3 because the reactants and products are all in 1:1 ratio.