9514 1404 393
Answer:
- boat: 48 km/h
- current: 14 km/h
Step-by-step explanation:
The upstream speed is ...
u = (204 km)/(6 h) = 34 km/h
The downstream speed is ...
d = (372 km)/(6 h) = 62 km/h
The speed of the boat in still water is the average of these values:
b = (34 kph +62 kph)/2 = 48 kph
The speed of the water is the difference between the boat's speed and the speed made good:
w = 48 -34 = 14 . . . km/h
The rate of the boat in still water is 48 km/h. The rate of the current is 14 km/h.
Answer:
The length of the rectangle 'l' = 20
The width of the rectangle 'w' = 14
Step-by-step explanation:
<u>Explanation</u>:-
Let 'x' be the width
Given data the length of a rectangular patio is 8 feet less than twice its width
2x-8 = length
The area of rectangle = length X width
Given area of rectangle = 280 square feet
x(2x-8) = 280
2(x)(x-4) =280
x(x-4) =140
x^2 -4x -140=0
x^2-14x+10x-140=0
x(x-14)+10(x-14)=0
(x+10)(x-14) =0
x = -10 and x = 14
we can choose only x =14
The width of the rectangle 14
The length of the rectangle 2x-8 = 2(14)-8 = 28 -8 =20
The length of the rectangle 'l' = 20
The width of the rectangle 'w' = 14
Answer:
B
Step-by-step explanation:
Answer:
C) Both functions are decreasing and both are positive on the interval (0;2)
Step-by-step explanation:
As known the exponent function has no minimum and has no maximum.
Otherwise exponent function can be only or increasing or decreasing for all x.
That means that in case y(x2)>y(x1) and if x2>x1- function is increasing.
That means that in case y(x2)<y(x1) and if x2>x1- function is decreasing.
Lets check what is going on with the function f(x)
If x1=0 f(x1)=24
If x2=2 f(x2)=0
So x2>x1 however f(x2)<f(x1)=> function is decreasing
Similarly g(x)
If x1=0 g(x1)=15
If x2=2 g(x2)=0
So x2>x1 however g(x2)<g(x1) => function is decreasing
So bothfunctions are decreasing.
Because f(x) is decreasing the function meaning with argument x1=0 has max in the interval x∈(0;2) And function meaning has the minimum if argument x2=2. So the function F(x) in interval (0;2) is changing from 24 to 0 => is positive on the interval (0,2)
The same is with g(x) . g(x) gonna be positive on the interval (0;2)
Answer:
A) C(d,m) = 40 + 55d + 0.13m
B) $448
Step-by-step explanation:
Let 'd' be the number of days and 'm' the number of miles driven.
A) The cost function that describes a fixed amount of $40, added to a variable amount of $55 per day (55d) and a variable amount of 13 cents per mile (0.13m) is:
B) If d = 5 and m =600, the total cost is:
The cost is $448.
