Could you please post the question idk if you see the person who commented above so i typed here but i will try to answer the questions when you post them!
Z < 6. Just divide each side by 5 :)
This year there are 900 rabbits which represents 200% of last year's population, means that last year the number of rabbits was:
x = 900 (100/200) = 450 rabbits.
The mathematical expression can be derived by a simple rule of three.
So, for last year the population was 450 rabbits.
2 right 3 up... hope this helped you