Change

[Natalie Espadas 1A]

I am unsure whether we have to use "-x" to the reactants and "+2x" to the product side according to what the question is asking or if we can use "+x" for reactants and "-2x" for the products as long as we use the same signs ( -/+ ) for the corresponding reactant and product side? Thank you in advance!

[Dabin Kang 1B]

Because the reactants are being used to make the product, the equilibrium concentration of the reactants would be less than the initial while the product's equilibrium concentration would be higher than its initial. Since we don't know the amount of reactants used to make the product, we would put it as x and subtract x from the reactants and add 2x to the product.

[Natalie Espadas 1A]

Thank you for the clarification!