This is third equation of motion. As there is no values given, I assume you just have to keep variable 'a' (representing acceleration) on one side of the equation and all other variables on the other side.
[tex] v_{f}^{2}= v_{o}^{2}+2a(x_{f}-x_{o}) [/tex]
[tex] v_{f}^{2}- v_{o}^{2}=2a(x_{f}-x_{o}) [/tex]
[tex] \frac{v_{f}^{2}- v_{o}^{2}}{2(x_{f}-x_{o})}=a [/tex]
OR
[tex] a=\frac{v_{f}^{2}- v_{o}^{2}}{2(x_{f}-x_{o})} [/tex]
Here, [tex] v_{o} [/tex] is initial velocity,
[tex] v_{f} [/tex] is final velocity ,
[tex] x_{o} [/tex] is initial position,
[tex] x_{f} [/tex] is final position, and
a is acceleration.
