Dear Sangeetha
You should not be confused with the inequalities. you should be able to physically interprete the things
Situation 1
V<0, a>0
suppose a particle is moving in the negative x direction hence at that instant say t1 v<0
suppose a force acts on it in the positive direction of x axis then acceleration will also be towrds +ve x axis. hence its magnitude of velocity in -ve direction of x axis will start decresing till the velocity becomes 0(say at time t2) then it will increase in magnitude and direction will become +ve x axis and V>0
hence velocity is-ve in the time interval t1 to t2.
and -ve and +ve  just show the direction and nothing else.
if Acceleration is in the direction of velocity then it will increase the velocity otherwise it will reduce the velocity,
 
Similarly you can think for the second case
 
All the best.                                                           
AKASH GOYAL
AskiitiansExpert-IITD
 
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