Disregarding the x in the Denominator

[Dustin Shin 2I]

When calculating the Ka or Kb, sometimes it will be given in a small number in which we are then allowed to disregard the x in the denominator. Will there ever be a case where we do not disregard the x in the denominator and have to use the quadratic formula or will we not have to concern ourselves with this for the upcoming final?

[Hovik Mike Mkryan 2I]

Hello,
It was mentioned previously that for the tests we should not approximate and use the quadratic formula unless stated otherwise. Hope this helps!