What is -n+8+n=-8n+8n-8

Please can someone help!

Rom4ik [11]

Answer:

51 mph

Step-by-step explanation:

→ The first thing we need is a formula which links speed, distance and time so,

Speed = Distance ÷ Time

Speed = mph

Distance = metres/miles

Time = hours

→ Since we want to work out the average speed of the entire journey we need to first work out the total distance and total time. Using the first sentence of the paragraph, it says that <em>the car travels at an average speed of 45 mph for 40 minutes, </em>we can rearrange the formula to work out the distance so,

Speed = Distance ÷ Time

→ Rearrange to get distance as subject

Distance = Speed × Time

→ Substitute in the values

Distance = 45 × 40

→ Remember that the time is hours but we substituted in minutes so we divide the time value by 60

40 ÷ 60 = 0.666666667

→ Substitute in the time value multiplied by the speed

Distance = 45 × 0.666666667 = 30

⇒ 30 metres/miles is overall distance for the first part of the journey

→ Now we have to work out the distance for the second part of the journey. State the distance formula.

Distance = Speed × Time

→ Substitute in the values into the distance formula

Distance = 60 × 25

→ Remember that the time is hours but we substituted in minutes so we divide the time value by 60

25 ÷ 60 = 0.416666667

→ Substitute in the time value multiplied by the speed

Distance = 60 × 0.416666667 = 25

⇒ 25 metres/miles is overall distance for the second part of the journey

→ Now we have to add the distance of both the journeys together

25 + 30 = 55

→ Then we add the times of the journey together

40 minutes + 25 minutes = 65 minutes

→ Convert 65 minutes into hours

65 ÷ 60 = 1.08333 hours

→ Substitute both values into the speed = distance ÷ time formula

Speed = 55 ÷ 1.08333 = 50.76923077

→ The question says to round it to the nearest whole number so,

50.76923077 = 51 mph

7 0

3 years ago

g In 2013, the Pew Research Foundation reported that 43% of U.S. adults report that they live with one or more chronic condition

SOVA2 [1]

Answer:

We are 95% confident that the true proportion of U.S. adults who live with one or more chronic conditions is between 39.7% and 46.33%

Step-by-step explanation:

From the question we are told that

The sample proportion is $\r p = 43\% = 0.43$

The standard error is $SE = 0.017$

Given that the confidence level is 95% then the level of significance is mathematically represented as

$\alpha = (100-95)\%$

=> $\alpha = 0.05$

Generally from the normal distribution table the critical value of $\frac{\alpha }{2}$ is

$Z_{\frac{\alpha }{2} } = 1.96$

Generally the margin of error is mathematically represented as

$E = Z_{\frac{\alpha }{2} } * SE$

=> $E = 1.96 * 0.017$

=> $E = 0.03332$

Generally 95% confidence interval is mathematically represented as

$\r p -E < p < \r p +E$

=> $0.43 -0.03332 < p < 0.43 + 0.03332$

=> $0.39668 < p < 0.46332$

Converting to percentage

$(0.39668 * 100)< p < (0.46332*100)$

$39.7\% < p < 46.33 \%$

7 0

3 years ago

Please help..Thanks:)

finlep [7]

From top to bottom: 16, 5, 28. Please give me 'brainliest answer?

8 0

3 years ago

Read 2 more answers

Solving Quadratic Equations using the Square Root Property

Afina-wow [57]

Answer:

$x = -2$ or $x = -5$

Step-by-step explanation:

You need to complete the square before you can take the square root of both sides.

$x^2 + 7x + 10 = 0$

Subtract 10 from both sides.

$x^2 + 7x = -10$

To complete the square, you need to add the square of half of the x-term coefficient to both sides.

The x-term coefficient is 7. Half of that is 7/2. Square it to get 49/4. Now we add 49/4 to both sides of the equation.

$x^2 + 7x + \dfrac{49}{4} = -10 + \dfrac{49}{4}$

$(x + \dfrac{7}{2})^2 = -\dfrac{40}{4} + \dfrac{49}{4}$

$(x + \dfrac{7}{2})^2 = \dfrac{9}{4}$

Now we use the square root property, if

$x^2 = k$ , then

$x = \pm \sqrt{k}$

$x + \dfrac{7}{2} = \pm \sqrt{\dfrac{9}{4}}$

$x + \dfrac{7}{2} = \pm \dfrac{3}{2}$

$x + \dfrac{7}{2} = \dfrac{3}{2}$ or $x + \dfrac{7}{2} = -\dfrac{3}{2}$

$x = -\dfrac{4}{2}$ or $x = -\dfrac{10}{2}$

$x = -2$ or $x = -5$

5 0

3 years ago

Find the circumference in inches

Alborosie

Answer:

Step-by-step explanation:

2×radius with pi, 28*pi=28 pi or 87.92

3 0

3 years ago

Read 2 more answers