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2 years ago

Hi there, I subscribed for one year but I don't know why it's telling me to upgrade again.

2 answers:

8 0

They might be a glitch or something for your payment Method that could be what it is maybe email about it or something hope that helps

aniked [119]2 years ago

3 0

Answer:

It could be a glitch or your payment method isn't working, also check your email to see if there are any updates from brainly. Brainly could also be encouraging you to upgrade to a different plan as-well.

You might be interested in

A particle moves on the hyperbola xy=18 for time t≥0 seconds. At a certain instant, y=6 and dydt=8. What is x that this instant?

professor190 [17]

Answer:

The value of x at this instant is 3.

Step-by-step explanation:

Let $x\cdot y = 18$ , we get an additional equation by implicit differentiation:

$x\cdot \frac{dy}{dt}+y\cdot \frac{dx}{dt} = 0$ (1)

From the first equation we find that:

$x = \frac{18}{y}$ (2)

By applying (2) in (1), we get the resulting expression:

$\frac{18}{y}\cdot \frac{dy}{dt}+y\cdot \frac{dx}{dt} = 0$ (3)

$y\cdot \frac{dx}{dt}=-\frac{18}{y}\cdot \frac{dy}{dt}$

$\frac{dx}{dt} = -\frac{18}{y^{2}} \cdot \frac{dy}{dt}$

If we know that $y = 6$ and $\frac{dy}{dt} = 8$ , then the first derivative of x in time is:

$\frac{dx}{dt} = -\frac{18}{6^{2}} \cdot (8)$

$\frac{dx}{dt} = -4$

From (1) we determine the value of x at this instant:

$x\cdot \frac{dy}{dt} = -y\cdot \frac{dx}{dt}$

$x = -y\cdot \left(\frac{\frac{dx}{dt} }{\frac{dy}{dt} } \right)$

$x = -6\cdot \left(\frac{-4}{8} \right)$

$x = 3$

The value of x at this instant is 3.

4 0

2 years ago

Whats is the answer -2/3 (-1 1/6)

grin007 [14]

Answer:

$\frac79$

Step-by-step explanation:

$\frac{-2}{3} \cdot-1\frac{1}{6}$

Let's convert the mixed number to an important fraction.

-1 1/6 = -7/6

Now multiply:

$\frac{-2}{3} \cdot \frac{-7}{6} = \\\\\\\frac{-2\cdot-7}{3\cdot6} = \\\\\\\frac{14}{18} = \frac79$

-Chetan K

7 0

2 years ago

Perry finished a 100-meter race in 7/8 of a minute. The winner of the race used 14/15 of Perry's time to finish the race. How mu

konstantin123 [22]

Answer:

49 seconds

Step-by-step explanation:

The time perry used is 7/8 of a minute

a minute equals to 60 seconds

so the time perry used is 7/8 x 60 = 52.5 seconds

The winner used 14/15 of 52.5 seconds (perrys time)

so 14/15 x 52.5 = 49 seconds

3 0

2 years ago

In a dilation with a scale factor of 3/4,the image is __________ the preimage

3241004551 [841]

I would say smaller than because you would be dilating the image by a number less than 1, which is making the image smaller.

3 0

3 years ago

A recent survey based on a random sample of n=470 voters, predicted that independent candidate for the mayoral election will get

julsineya [31]

I have an expression

$\sigma = \sqrt{p(1-p)/n}$

floating around in my head; let's see if it makes sense.

The variance of binary valued random variable b that comes up 1 with probability p (so has mean p) is

$E( (b-p)^2 ) = (-p)^2(1-p) + (1-p)^2p = p(1-p)$

That's for an individual sample. For the observed average we divide by n, and for the standard deviation we take the square root:

$\sigma = \sqrt{p(1-p)/n}$

Plugging in the numbers,

$\sigma = \sqrt{.24(1-.24)/490} = 0.019 = 1.9\%$

One standard deviation of the average is almost 2% so a 27% outcome was 3/1.9 = 1.6 standard deviations from the mean, corresponding to a two sided probability of a bit bigger than 10% of happening by chance.

So this is borderline suspect; most surveys will include a two sigma margin of error, say plus or minus 4 percent here, and the results were within those bounds.

7 0

3 years ago