For this case we have the following polynomial:

What we must do for this case is to factor the polynomial, so that we have:
1) The number of bottles
2) the weight of each bottle.
We have then:

Answer:
A factorization that could represent the number of water bottles and weight of each water bottle is:

x has two values 4 and 5 by factorization or using the general formula
Answer:
(x+3)²-11=0
Step-by-step explanation:
0=9(x2+6x)-18
0= 9x² +54x-18
0= 9( x²+6x-2) taking 9 common
0= x² +6x-2 (breaking the mid term to find the second element of the square
0 = (x)² +2(x)(3) +(3)² -2 -9 adding and subtracting the second element
0= (x+3)² -11 summing up