A500 kg compact car and a 1500 kg truck are accelerated equally. which vehicle exerts more force? how many times more?
(im guessing the 1500kg truck exerts more force but i don't know how to solve for how many times more)

The truck doesn't "exert more force".

It TAKES more force to accelerate the truck at the same rate
as the car, because the truck has more mass.

Think: 
In order to move two rocks, you have to push harder on the heavy one
than you do on the lighter one.

How much more ?

In order to produce the same acceleration . . .

                    half as much mass  ===>  half as much force

                   twice as much mass ===> twice as much force

             ten times as much mass ===> ten times as much force

 a 1500-kg truck
     compared to
  a 500-kg car . . . triple the mass ===> triple the force, in order
                                                               to accelerate them equally .