11.59

[Vanessa Reyes_1K]

After using the quadratic to solve for x, how do we know which outcome is valid if both numbers are positive?

[Eshwar Venkat 1F]

To check, you can plug the two x values back into the ICE table. In cases like this, usually when you plug in the larger x value, it results in the equilibrium concentrations of both reactants being less than 0, which cannot happen.

[Gary Qiao 1D]

If you plug in the larger positive x value, you will find that the equilibrium concentrations of the reactants are negative, and that is not possible, meaning that value can be disregarded. Therefore, there would be only one valid x value.

[Ian Marquez 2K]

For the two options, if both are positive, plug it into the ICE table and make sure that your equilibrium concentration is still positive. If x is too large then this will be negative which cannot happen. In any case, it is good to check both solutions if unsure, especially if both are positive values.