Use Algebra to solve $\displaystyle v_2$ = $\displaystyle v_1$ + $\displaystyle at$ for $\displaystyle v_1$ if $\displaystyle v_2$ = 245m/s, a= 19m/s squared, and t = 22s

I just want to be put on the right track... now I seen many examples for this online. I just am primiarily confused because of the units of time and speed.