Answer:
digestive would be stomach, excretion is the big and small intestines
Step-by-step explanation:
stomach digests food, your intestines process whatever is left till you excrete
How to solve this: (in case you need it)
4n-18=52
4n-18+18=52+18
4n=70
4n/4=70/4
n=35/2
The first differences are 8, 14, 20.
The second differences are 6.
Half of 6 is 3, so the first term of the sequence is 3n^2.
If you subtract 3n^2 from the sequence you get 0,-1,-2,-3 which has the nth term of -n + 1.
Therefore your final answer will be 3n^2 - n + 1
10 divided by 2 minus 1 equals 4