Answer
Subtract
from 
then;

Remove the bracket we have;

Like terms are those terms which have same variable to the same power.
Combine like terms;

Therefore, Subtracting
from
we get 
The answer to number 17 is c
Circumference = ππD
Circumference = 8.4π cm
S + 2l = 1372
s + l =858
s + 2l = 1372
-s - l =. - 858
l= 514 grams a large bottle
s + 514= 858
s = 344 grams a small bottle