Step-by-step explanation:
A)
The length of the box is 30 − 2x inches.
The width of the box is 30 − 2x inches.
The height of the box is x inches.
So the volume is:
V = x (30 − 2x)²
B)
V(3) = 3 (30 − 6)² = 1728
V(4) = 4 (30 − 8)² = 1936
V(5) = 5 (30 − 10)² = 2000
V(6) = 6 (30 − 12)² = 1944
V(7) = 7 (30 − 14)² = 1792
As x increases, the volume of the box increases to a maximum and then decreases.
C)
The ends of the domain occur when V = 0.
0 = x (30 − 2x)²
x = 0 or 15
So the domain is (0, 15).
IIIIIIIIIIIIIIIIIIIIIIIIII HHHHHHHHHHAAAAAAAAAAAVE NOOOO CLUE
The first thing you should know for this problem is the definition of speed.Speed is defined as the quotient between distance and time.
v = d / t.
Substituting the values, we have:
v = (100 + 400) / (30) = 16.67 m / s
answer
the train going at 16.67 m / s
4 pints
i hope this helped, thank you! :)