The rule of product states that:
So, a product is positive if and only if both factors have the same sign, and is negative if only if the factors have opposite sign.
For this case, the first thing we must do is define variables.
We have then:
x: number of pens
y: number of pencils
We now write the system of inequations:

The solution to the system of inequations is given by the shaded region.
Note: see attached image.
Answer:
The acceleration of the car will be 400 m/s².
Step-by-step explanation:
The acceleration of the car can be found using Newton second law:
Where:
F: is the net force = 200 N
m: is the mass = 500 g
a: is the acceleration =?
Then, the acceleration will be:
Therefore, the acceleration of the car will be 400 m/s².
I hope it helps you!