-8=-(x+4) what does x equal

A boat on a river travels downstream between two points, 20 mi apart, in one hour. The return trip against the current takes 2 1

kondaur [170]

Answer:

The speed of boat in still water is 14 miles per hour.

The speed of current is 6 miles per hour.

Step-by-step explanation:

Let v represent the speed of boat in still water and c represent speed of current.

We have been given that a boat on a river travels downstream between two points, 20 miles apart, in one hour.

The speed of boat downstream would speed of boat in still water plus speed of current that is $(v+c)$ .

The return trip against the current takes 2 1/ 2 hours. The speed of boat against current would speed of boat in still water minus speed of current that is $(v-c)$ .

$\text{Speed}=\frac{\text{Distance}}{\text{Time}}$

Substituting our given values, we will get:

$v+c=\frac{20}{1}...(1)$

$v-c=\frac{20}{2.5}...(2)$

Adding both equations, we will get:

$v+c+(v-c)=\frac{20}{1}+\frac{20}{2.5}$

$v+c+v-c=\frac{20}{1}+\frac{20}{2.5}$

$2v=20+8$

$2v=28$

$\frac{2v}{2}=\frac{28}{2}$

$v=14$

Therefore, the speed of boat in still water is 14 miles per hour.

To find the speed of the current in the river, we will substitute $v=14$ in equation (1) as:

$14+c=\frac{20}{1}$

$14+c=20$

$14-14+c=20-14$

$c=6$

Therefore, the speed of current is 6 miles per hour.

3 0

3 years ago

Which golf ball went higher, and how many feet? (Desmos!) - Just added the answer choices!

lora16 [44]

Answer:

Max height: 64 feet, and the socond one was higher.

Step-by-step explanation:

The max height is the y value of the vertex, because that’s when the graph peaks.

we can already very clearly see the vertex on the graph, so we don’t need to calculate it.

the max height of the second golf ball is 64 feet.

Now let’s look at the max height on the first golf ball.

we get the equation

h=-16t squared + 48t

to find the vertex of this, we can use the formula -b/2a

-48/-32 = 1.5

1.5 is the t value of this vertex.

to find the h value, we plug it in.

h = -16 (1.5) squared + 48(1.5)

h =2.25 times -16 + 72

h = -36 +72

h = 36

the first one is 36 max height, and the second is 64. The second one is bigger.

8 0

3 years ago

Ill give brainiest to, whom ever gets this correct.

Dovator [93]

Answer:

50.2 m^2

Step-by-step explanation:

The Area of a circle is given by the equation pi(r)^2

Therefore if r = 4 we can plug it into the equation to get:

pi (4)^2
= pi(16)
= 50.2655 or about 50.2 m^2

3 0

3 years ago

Read 2 more answers

Micheal runs 7 miles in 80 minutes. At the same rate, how many miles would he run in 64 minutes?

ANEK [815]

Micheal's rate is 7 miles per 80 minutes, which can be written as a fraction:
7/80, which equals 0.0875.
Now you can say that Micheal runs 0.0875 miles per one minute.
Multiply 0.0875 by 64,
64(0.0875) = 5.6

Micheal would run 5.6 miles in 64 minutes.

7 0

4 years ago

From Monday through Friday, James works in the library on 2 days and in the cafeteria on another day. On Saturday and Sunday, Ja

Veseljchak [2.6K]

Answer:

4

60%

Step-by-step explanation:

To find how many days James works in the week we first need to analyze the problem.

Monday to Friday = 5 days

On 2 days he works in a library.

On another day he works in the cafeteria.

So that means that James works.

2 days Library + 1 day Cafeteria = 3 days.

Now on Saturday and Sunday James works 50% of the days.

Saturday and Sunday = 2 days

50% of 2 = 1

So James works 1 day on Saturday and Sundays.

How many days does James work in the week?

Weekdays = 3

Weekend = 1

So James works 4 days in a week.

What percent of the days from Monday through Friday does he work?

James works 3 days of Monday through Friday

Since there are a total of 5 days from Monday through Friday, we can express it like this:

$\dfrac{3Days}{5Days}$

$\dfrac{3Days}{5Days}=0.6$

Now to find the percentage, we multiply the total to 100.

0.6 x 100 = 60%

4 0

4 years ago