Physics Question. Which equation do i use to slove this problem.

This is a weird question - you are not even told what you have as the wording is "known and unknown"

In the first equation you do not have v but you have all the others so maybe you could use that

in the second equation you do not have initial displacement (usually considered to be 0 but maybe not here)

you might have everything else so maybe you could use that.    :///