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3 years ago

The equation for the circle below is the x2 + y2=81. what is the length of the circles radius

Mathematics

2 answers:

larisa [96]3 years ago

8 0

Answer:

Step-by-step explanation:

Compare your x2 + y2=81 to the following:

x^2 + y^2 = 81

The " ^ " symbol indicates exponentiation.

Now compare x^2 + y^2 = 81 to

x^2 + y^2 = r^2.

This is the standard equation of a circle of radius r centered at the origin, (0,0). You can see for yourself that 81 must equal r^2.

Taking the square root of 81, we get plus or minus 9.

But the radius must be positive, so we reject the -9 and take +9.

The radius is 9.

SSSSS [86.1K]3 years ago

8 0

Answer: 9

Step-by-step explanation:

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What is the median and mean amount of sugar? pictures attached

mario62 [17]

Answer:

Step-by-step explanation:

mean is found by adding the numbers and dividing the sum by the number while the median is the middle value of the list ordered in an ascending order

4 0

2 years ago

Rebecca went swimming yesterday. After a while she had covered one fifth of her intended distance. After swimming six more lengt

alukav5142 [94]

Answer:

Option E.

Step-by-step explanation:

Let the intended length of Rebecca's swimming is = x units

and we assume the length of the pool = l units

Now it is given in the question that " She covers one fifth of her intended distance "

That means distance covered = $\frac{x}{5}$

" After swimming six more lengths of the pool she had covered one quarter of her intended distance"

So $\frac{x}{5}+6(l)=\frac{x}{4}$

$6l=\frac{x}{4}-\frac{x}{5}$

$6l=\frac{x}{20}$

x = 20×(6l)

x = 120l

Therefore, Rebecca has to complete 120 lengths of the pool.

Option E is the answer.

4 0

3 years ago

4, 12, 20 what the common diffrence?? help im timed

sdas [7]

It goes by 8!

If u see, 4 + 8= 12 +(another) 8 = 20! It skips 8 every time!

If u were to continue it, 20 + 8 = 28 and so on!
The difference is the sum of the number totalled.

Hope this helps!

4 0

3 years ago

Solve x<3 and x≥−1 and write the solution in interval notation. If there is no solution, type ∅ .

bearhunter [10]

Shown in the Figure below

Step-by-step explanation:

In this exercise, we have the following system of inequalities:

$x$

The word and means intersection, so both inequalities must be true at the same time. We can graph this system as indicated in the figure below. Indeed, there is intersection between -1 and 1. Also, the number -1 is included in the solution because $x\geq -1$ and this is represented by the closed circle. On the other hand, the number 3 is not included in the solution because $x$ and this is represented by the open circle.

<h2>Learn more:</h2>

Inequalities: brainly.com/question/12261425

#LearnWithBrainly

7 0

3 years ago

A car's velocity is modeled by

Igoryamba

In accordance with the function <em>velocity</em>, the car will have a complete stop after 6 seconds.

Herein we have a function of the velocity of a car (v), in feet per second, in terms of time (t), in seconds. The car stops for t > 0 and v = 0, then we have the following expression:

0.5 · t² - 10.5 · t + 45 = 0

t² - 21 · t + 90 = 0

By the <em>quadratic</em> formula we get the following two roots: t₁ = 15, t₂ = 6. The <em>stopping</em> time is the <em>least</em> root of the <em>quadratic</em> equation, that is, the car will have a complete stop after 6 seconds.

To learn more on quadratic equations: brainly.com/question/2263981

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8 0

2 years ago