Plz help me! Thanks!

The runner has to race for 21km. She has to finish race before 1h 40min. What avarage speed She has to run to gain such goal?

abruzzese [7]

Answer:

The rate of the runner is 3.5 meters per second.

Step-by-step explanation:

To get this answer in meters per second, we first have to convert each of the terms into either meters or seconds. We can do that by multiplying by unit rates.

21 km * 1000 = 21,000 meters

1 hour * 3600 = 3,600 seconds

40 minutes * 60 = 2,400 seconds

Now we divide the meters by the total number of seconds to get the rate.

21,000 meters / (3,600 + 2,400) secs

21,000 meters / 6,000 secs

3.5 meters per second.

7 0

3 years ago

Is (3,4) a solution to the system of<br> equations. <br> X + y = 7<br> x - 2y = - 5

Anuta_ua [19.1K]

Answer: Yes, the point (3,4) is a solution to the system.

===================================================

Proof of this:

Replace x with 3 and y with 4 in the first equation

x+y = 7

3+4 = 7

7 = 7

This confirms the first equation. Repeat for the second equation

x-2y = -5

3-2(4) = -5

3 - 8 = -5

-5 = -5

We get true equations for both when we plug in (x,y) = (3,4). This confirms it is a valid solution to the system of equations. It turns out it's the only solution to this system of equations. Visually, the two lines cross at the single location (3,4).

8 0

3 years ago

how does the appearence of a histogram change when u use many small intervals then when you use a few large intervals

vampirchik [111]

If you're using a few larger intervals, then your histogram looks more stocky. If you imagine drawing one, it's because you're adding more values into the same category which can make the difference between two intervals much more noticeable. If you're using smaller intervals, however, you can much more accurately assess the difference between two different intervals. For that reason, the transition between one and another interval would look much more 'fluid'.

5 0

3 years ago

Please help is needed urgently! 8th grade math question?!

AURORKA [14]

ratio of the diagonal to the side of the rectangle is 17/8 or 17:8

Step-by-step explanation:

Length of Diagonal = 34 inches

Length of side = 16 inches

Base= 30 inches

We need to find the ratio of the diagonal to the side of the rectangle.

ratio of the diagonal to the side of the rectangle = $\frac{length of diagonal}{length of side}$

Putting values:

$Ratio=\frac{34}{16} \\Simplifying:\\Ratio=\frac{17}{8}$

So, ratio of the diagonal to the side of the rectangle is 17/8 or 17:8

Keywords: ratio

Learn more about ratio at:

#learnwithBrainly

6 0

3 years ago

Find the x-intercept of the parabola with vertex (1,-13) and y-intercept (0,-11).

Advocard [28]

1. find equation

general solutions are:
$y = a x^{2} +bx +c \\ \\ \frac{dy}{dx} = 2ax +b$

for P(0,-11)

$-11 = 0a + 0b +c$ ⇒ $c = -11$

for p(1,-13)
$-13 = 1a + 1b -11 \\ a+b = -2$

and

$0 = 2a + b \\ b = -2a$

solve for a and b:
$a - 2a = -2 \\ a = 2 \\ b = -4$

the total equation is now:

$y = 2 x^{2} -4x -11$

To find the x-intercept set y=0 and solve for x

$0 = 2 x^{2} -4x-11$

4 0

3 years ago

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