Hi Sasha,

How I recommended that my students solve those problems is to use estimation. For that particular chemistry equation, I told them to treat the [H+] as 10^-8 + 10^-7. That gives 1.1^-7 which is close enough to the actual value to help you guess the correct answer once you solve for it.

For the kinematics equation, there will usually be a way to either eliminate one or two of the components on the right of that equation. As far as I know, I have never seen the need to know how to manipulate the quadratic formula on the MCAT.