All categories

3 years ago

Hello, Can someone please help me with this math problem? thanks!

Mathematics

1 answer:

Elis [28]3 years ago

5 0

I believe it's A) because the conjugate of any number is basically inverted signs when multiplying a binomial, so [-2 - √b][-2 + √b]. It's A).

You might be interested in

The time between telephone calls to a cable television service call center follows an exponential distribution with a mean of 1.

Ulleksa [173]

Answer:

0.52763 is the probability that the time between the next two calls will be 54 seconds or less.

0.19285 is the probability that the time between the next two calls will be greater than 118.5 seconds.

Step-by-step explanation:

We are given the following information in the question:

The time between telephone calls to a cable television service call center follows an exponential distribution with a mean of 1.2 minutes.

The distribution function can be written as:

$f(x) = \lambda e^{-\lambda x}\\\text{where lambda is the parameter}\\\\\text{Mean} = \mu = \displaystyle\frac{1}{\lambda}\\\\\Rightarrow 1.2 = \frac{1}{\lambda}\\\\\lambda = 0.84 \\f(x) = 0.84 e^{0.84 x}$

The probability for exponential distribution is given as:

$P( x \leq a) = 1 - e^{\frac{-a}{\mu}}\\\\P(a \leq x \leq b) = e^{\frac{-a}{\mu} -\frac{-b}{\mu}}$

a) P( time between the next two calls will be 54 seconds or less)

$P( x \leq 0.9)\\= 1 - e^{\frac{\frac{-54}{60}}{1.2}} = 0.52763$

0.52763 is the probability that the time between the next two calls will be 54 seconds or less.

b) P(time between the next two calls will be greater than 118.5 seconds)

$p( x > \frac{118.5}{60}) = P(x > 1.975)\\\\ = 1 - P(x \leq 1.975) \\\\= 1 -1+ e^{\frac{-1.975}{1.2}}\\\\= 0.19285$

0.19285 is the probability that the time between the next two calls will be greater than 118.5 seconds.

6 0

3 years ago

A bus covers 270km distance in 6 hours.

pentagon [3]

Answer:

(i)= 45 KPH, (ii) = 251 miles

Step-by-step explanation:

'Per' essentially means divide. Thus, to find Kilometres per hour, divide 270 by 6= 45. The bus is travelling at 45 KPH.

Then, to see how far a nine hour trip would cover, distance = speed * time = 251 miles.

7 0

2 years ago

What's the anwser to 5 6 7

ExtremeBDS [4]

5: n=135
6: n=3
7: n=214

3 0

3 years ago

Read 2 more answers

Find the value of x.<br> helpppp

Bezzdna [24]

Answer: $55^{\circ}$

Step-by-step explanation:

The measure of the third unknown arc is

$360^{\circ}-70^{\circ}-110^{\circ}=180^{\circ}$ .

So, $x=\frac{180^{\circ}-70^{\circ}}{2}=\boxed{55^{\circ}}$

8 0

2 years ago

A youth group is setting up camp. Rain is predicted, so the campers decide to build a fly, or rain cover, over their tent. The f

pshichka [43]

The image for this is attached for reference. This problem can be used by the Pythagorean equation. To make solving convenient, let us see only one part of the tent. Hence, one side is half of the tend width which is 16/2ft. Height is 12 ft. The unknown side is the hypotenuse. The answer is:
$a^{2} + b^{2} = c^{2} 8^{2} + 12^{2} = c^{2} c = 14.4$

7 0

3 years ago