5k²-8k-45k+72 = 5k²-53k+72
Answer: 5k² - 53k + 72
Answer:
0.5hrs
Step-by-step explanation:
Let the speed downhill be
,
Speed uphill is
. We are told than speed uphill is
the speed on flat ground. Therefore the speed on level ground will be
.
From this info, we can obtain the actual speed,
on level ground as:

speed, distance and time have the relation
so to obtain time to cover 45miles:

Hence it takes 0.5hrs to cover 45miles on flat ground.
Enter a problem...
Calculus Examples
Popular Problems Calculus Find the Domain and Range f(x)=5x-3
f
(
x
)
=
5
x
−
3
The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression undefined.
Interval Notation:
(
−
∞
,
∞
)
Set-Builder Notation:
{
x
|
x
∈
R
}
The range is the set of all valid
y
values. Use the graph to find the range.
Interval Notation:
(
−
∞
,
∞
)
Set-Builder Notation:
{
y
|
y
∈
R
}
Determine the domain and range.
Domain:
(
−
∞
,
∞
)
,
{
x
|
x
∈
R
}
Range:
(
−
∞
,
∞
)
,
{
y
|
y
∈
R
}
Number of returns = 47
Number of returns that contain errors = 5
Number of returns that does not contain error = 47 - 5 = 42
P(selecting none that contains error in the unreplaced selection) = 42/47 x 41/46 x 40/45 = 68880 / 97290 = 0.708
option C is the correct answer.