Mathematics, 19.05.2020 03:12 tikirawallace

You are wakeboarding on a river. You travel 2 miles downstream to a marina for supplies, and then you travel 3 miles upstream to a dock. The boat travels x miles per hour during the entire trip, and the river current is 3 miles per hour.

How long will the trip take when then speed of the boat is 18 miles per hour? Round to the nearest tenth minute.

Answers: 2

Show answers

Answers

Answer from: jonathanmontalv

Let x represent the speed of of boat.

We have been given that the river current is 3 miles per hour.

The speed of boat upstream will be x-3 .

The speed of boat downstream would be x+3 .

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

We have been given that you travel 2 miles downstream to a marina for supplies, and then you travel 3 miles upstream to a dock.

We can represent this information in an equation as:

$\text{Time}=\frac{2}{x+3}+\frac{3}{x-3}$

Since the speed of the boat is 18 miles per hour, so we will substitute x=18 in above equation and solve for time.

$\text{Time}=\frac{2}{18+3}+\frac{3}{18-3}$

$\text{Time}=\frac{2}{21}+\frac{3}{15}$

$\text{Time}=\frac{2}{21}+\frac{1}{5}$

$\text{Time}=\frac{2\cdot 5}{21\cdot 5}+\frac{1\cdot 21}{5\cdot 21}$

$\text{Time}=\frac{10}{105}+\frac{21}{105}$

$\text{Time}=\frac{31}{105}$

$\text{Time}=0.295238095$

Since time is in hours, so let us convert our given time in minutes.

1 hour = 60 minutes.

$\text{Time}=0.295238095\times 60\text{ minutes}$

$\text{Time}=17.7142857\text{ minutes}$

Rounding to nearest tenth of minute.

$\text{Time}\approx 17.7\text{ minutes}$

Therefore, it will take approximately 17.7 minutes for the boat to take the trip.

Answer from: Quest

x/3-10=8

x/3=18

x=48

Answer from: Quest

starting with:

5 + x - 12 = 2x - 7

5 + x - 12 - x = 2x - 7 - x (subtract x from both sides)

5 - 12 = x - 7 (combine and cancel x's from both sides)

5 - 12 + 7 = x - 7 + 7 (add 7 to both sides)

0 = x (add numbers together on both sides)

so in order for the equation to be true, x must be 0.

trying x = -0.5

5 + x - 12 = 2x - 7 (original equation)

5 + -0.5 - 12 = 2(-0.5) - 7 (plug in value of x)

5 + -0.5 - 12 = -1 - 7 (did multiplication)

-7.5 = -8 (did addition on both sides)

since -7.5 is obviously not equal to -8, the value of -0.5 for x is wrong.

trying x = 0

5 + x - 12 = 2x - 7 (original equation)

5 + 0 - 12 = 2(0) - 7 (plug in value of x)

5 + 0 - 12 = 0 - 7 (did multiplication)

-7 = -7 (did addition on both sides)

since -7 equals -7, that demonstrates that the value of 0 for x is correct.

trying x = 1

5 + x - 12 = 2x - 7 (original equation)

5 + 1 - 12 = 2(1) - 7 (plug in value of x)

5 + 1 - 12 = 2 - 7 (did multiplication)

-6 = -5 (did addition on both sides)

since -6 is obviously not equal to -5, the value of 1 for x is wrong.

Another question on Mathematics

Mathematics, 21.06.2019 15:30

Michelle had a birthday party. she bought a bag of candy with 96 starbursts, 72 hershey's, and 68 reese's. she wants to use all the candy she bought to make goody bags with the same amount of starbursts, hershey's and reese's in each bag. what is the largest number of bags she can make?

Answers: 1

Answer

Mathematics, 21.06.2019 17:00

The following graph shows the consumer price index (cpi) for a fictional country from 1970 to 1980? a.) 1976 - 1978b.) 1972 - 1974c.) 1974 - 1976d.) 1978 - 1980

Answers: 1

Answer

Mathematics, 21.06.2019 18:00

If the cost to mail a package is an initial $5 and $0.28 for every pound the total cost to mail a package was $11.27, how much did the package weigh?

Answers: 1

Answer

Mathematics, 21.06.2019 18:00

Simplify the expression. -2/5(10+15m-20n)

Answers: 1

Answer

You know the right answer?

You are wakeboarding on a river. You travel 2 miles downstream to a marina for supplies, and then yo...