Physics problems

Just two physics problems involving kinematics. I have the answers but I don't know how to get to them. Any help would be appreciated.

The problems:

1) An object moving at constant acceleration covers two equal, consecutive, 11 m long segments, the first one in t1 = 0.93s and the second one in t2 = 2.05s . What was the speed of the object (in m/s) at the beginning of the first segment?

Answer: 15.5

2) A terain vehicle, from its intial position, point A should reach a point D which is d= 12.8 km away from the straight road on which the vehicle is on. The point on the road closest to the point D is the point C. The speed of the vehicle while on the road is Vr= 56 km/h while the speed of the vehicle outside of the road is Vt= 34 km/h. Assuming that the vehicle will move along a straight line from point B where it leaves the road, calculate the distance BC so that the overall time ABD is minimum.

Answer: 9.8

I know the the wording is kinda shaky but I just copy pasta'ed it.

For second question:

distance from B to C: t

time of path: (t-A)/56  +  (sqrt((12.8)^2 + t^2))/34

derivative: 1/56 + 1/34 * ((12.8)^2 + t^2)^(-1/2) * 1/2 * 2t
 = 1/56 + 1/34 * ((12.8)^2 + t^2)^(-1/2) * t

Set it equal to 0:

-34/56 = (163.84 + t^2)^(-1/2) * t

1156/3136 = t^2/(163.84 + t^2)

t^2 - t^2 * (1156/3136) = 163.84 * (1156/3136)
t^2 * (1980/3136) = 163.84 * (1156/3136)
t^2 * 1980 = 163.84 * 1156
t = 9.78..