What is the result of solving this formula for A

making a as the subject of the formula will be as follows
[tex]\begin{gathered} v_f=u_s+at \\ v_f-u_s=at \\ \text{divide both sides by t} \\ \frac{v_f-u_s}{t}=\frac{at}{t} \\ a=\frac{v_f-u_s}{t} \end{gathered}[/tex]