DC Motor Speed ControL

I need very simple circuit to control the speed ,, is this circuit good ? will work fine knowing that each motor in the fig is 1.5A 24 volt

No, this is very bad. The transistors are shorting out the 24V supply. You should connect the motors between the emitters and ground (google "emitter follower") and connect the potentiometer to the bases.

Thx man , that was very helpful