The acceleration of a particle which moves along the x axis is given by a=4x+5x^(3/2)

The particle has speed of 2m/s when x=1m
x is in meters
a is in m/s^2

evaluate the velocity when x = 8m

I know that I need to use kinematic eqn 3

adr = vdv
then take the integral but I'm not sure where to take the limits from