If you have two negatives they cancel each other out and make a positive. The same if you have to positives the product will be positive. If you have a negative and a positive you multiply the numbers and bring down the negative. Same if you have a positive and a negative. Only two negatives cancel each other out, same with positives. For example -4(-5)(-1) you would use order of operations, 4 and the 5 cancel each other out and you multiply 20 by -1 which is -20 since you bring down the negative.
Let x be the page number then x+1 would be the other page number (because the pages are two facing pages which means they follow on consecutively)
Then
(x)(x+1) = 156
x^2 + x - 156 = 0
x = 12 or x = -13( but x can't be a negative number)
so x = 12
and the next page is 13
ANSWER
8π ft
EXPLANATION
The circumference of a circle is calculated using the formula C=πd.
Where d=8 is the diameter of the circle.
We substitute d=8 into the formula to obtain,
C=8π ft.
Because we are looking for the exact circumference, we leave the answer in terms of π.
check the picture below.
so, we know the dimensions of the pool, is a 20x10, so its area is simply 200 ft², and we know the walkway is 216 ft², so the whole thing, including pool and walkway is really 200 + 216 ft².
now, as you see in the picture, the dimensions for the combined area is 20+2x and 10+2x, since the walkway is "x" long, therefore,

notice, it cannot be -18, since is a positive length unit.