These ordered pairs, {(2,4) (3,6) (4,8) (5,10)}, are a function.

True

False

True

Step-by-step explanation:

In order for a relation (a set of ordered pairs) to be considered a function, every value in the domain (the set of all the first numbers in the pair) is associated with one value in the range (the set of all second numbers in the pair). This is easiest to see visually. Our domain is the set {2, 3, 4, 5} and our range is the set {4, 6, 8, 10}, and we can visualize the ordered pair (2, 4) as an "arrow" starting a 2 in the domain and ending at 4 in the range. When seen this way, a relation is a function if every value in the domain only has one arrow coming out of it. We can see from the attached picture that the ordered pairs in the problem are a function, so this statement is true.

width =  15 ft

length = 26 ft

Step-by-step explanation:

(19 - 2x)(30 - 2x) = 390

570 - 38x - 60x + 4x² = 390

combine like terms:

4x² - 98x + 570 = 390

subtract 390 from each side of the equation:

4x² - 98x + 180 = 0

divide by 4:

x² - 24.5 + 45 = 0

(x - 22.5)(x - 2) = 0

x = 22.5 and x = 2

since x = 22.5 is out of the usable range, x = 2 is the solution

width = 19 - 4 = 15 ft  (remember that there will be a 2 ft gap at each wall)

length = 30 - 4 = 26 ft (remember that there will be a 2 ft gap at each wall)