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Velocity is rate of change of distance, so, if x is distance, velocity,v is given by:

l.   2t + 5

ll.  1/2

lll.  t/2

lV. 2t + 3/4

Just plug in t = 5 (where approriate) to get the velocities.

could you show the entire process? i also forgot to mention that lim is deltaT→0

I'll do the first one for you:

x = t^2 + 5t + 2

v = Limit_dt→0 (x_t+dt - x_t)/dt             I'll use dt instead of writing out deltat all the time.

so

Put t+dt into the expression for x to get the x_t+dt part

v = Limit_dt→0  ([t+dt]^2 + 5[t+dt] + 2 - t^2 - 5t - 2])/dt 

Expand the terms in brackets

v = Limit_dt→0  (t^2 + 2tdt + dt^2 + 5t + 5dt + 2 - t^2 - 5t - 2])/dt 

Subtract terms where appropriate

v = Limit_dt→0  (2tdt + dt^2 + 5dt])/dt 

Divide numerator by dt

v = Limit_dt→0  (2t + dt + 5] 

Let dt go to zero and you are left with:

v = 2t + 5 

See if you can apply a similar approach with the others.