Its the old rabbit colony question using simultaneous linear and quadratic equations - and I need help:

Question

A colony of rabbits is growing so that the total number of rabbits (R) after number of weeks (t) is shown: on this table.

t=5 R=140, t=10 R=200, t=15 R=280, t=20 R=400, t=25 R=570, t=30 R=800

The food supply available is such that it can feed (N) of rabbits at any given time (t = weeks) according to the table:

t=5 N=440, t=10 R=480, t=15 R=520, t=20 R=560, t=25 R=600.

At what point in time is the population of rabbits and food balances?

I know I have to use simultaneous linear and quadratic equations - I just need to put them into equations first.

Thanks for the help.