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3 years ago

HELP ME REALLY QUICK FOR 20 points.

Mathematics

2 answers:

Debora [2.8K]3 years ago

7 0

Answer:

radius

Step-by-step explanation:

kolbaska11 [484]3 years ago

6 0

Answer:

C. Diameter. It only gives you half the points you selected so you selected 20 points we only get 10 points.

Step-by-step explanation:

You might be interested in

Given: circle k(O), ED diameter, m∠OEF=32°, m EF=(2x+10)°. Find: x

Snezhnost [94]

Answer:

The value of x is $53\°$

Step-by-step explanation:

see the attached figure to better understand the problem

step 1

Find the measure of arc DF

we know that

The inscribed angle measures half that of the arc comprising

$m$

we have

$m$

substitute

$32\°=\frac{1}{2}(arc\ DF)\\ arc\ DF=64\°$

step 2

Find the measure of x

we know that

$arc\ DF+arc\ EF=180\°$ ---> is a semi circle

we have

$arc\ DF=64\°\\ arc\ EF=(2x+10)\°$

substitute

$64\°+(2x+10)\°=180\°\\ 2x\°=180\°-74\°\\ 2x\°=106\°\\ x=53\°$

4 0

4 years ago

there are n counters in a bag. 4 of the counters are red and the rest are blue. Ross takes a counter from the bag at random and

Ainat [17]

Answer: n = 10.

Step-by-step explanation:

In the bag, we have n counters.

4 of the counters are red.

the rest are blue, then we have:

(n - 4) blue counters.

Now, the probability that Ross takes a blue counter from the bag is equal to the quotient between the number of blue counters (n - 4) and the total number of counters, n

Then the probability is:

p1 = (n - 4)/n

Now he draws another, and it must be blue again, then we can calculate the probability in the same way as above, but he already take a blue counter, so the number of blue counters is (n - 5) and the total number of counters is (n - 1)

The probability of this event is:

p2 = (n - 5)/(n - 1)

The joint probability (the probability that Ross takes two blue counters) is equal to the product of the individual probabilities, and we know that this is equal to 1/3, then we have the equation:

1/3 = ( (n - 4)/n)*((n - 5)/(n - 1))

Now let's solve this for n.

n*(n - 1)/3 = (n - 4)*(n - 5)

(n^2 - n)/3 = n^2 - 4*n - 5*n + 20

n^2 - n = 3*(n^2 - 9*n + 20)

n^2 - n = 3*n^2 - 27*n + 60

0 = (3*n^2 - n^2) - 27*n + n + 60

0 = 2*n^2 - 26*n + 60

The two solutions of this equation can be found with Bhaskara's equation:

$n = \frac{-(-26) +- \sqrt{(-26)^2 - 4*2*60} }{2*2} = \frac{26+- 14}{4}$

Then the two solutions are:

n = (26 - 14)/4 = 3

This is not an option, because we know for sure that we have 4 red counters, then this option can be discarded.

The other solution is:

n = (26 + 14)/4 = 40/4 = 10

Then we have n = 10, 10 counters in total.

4 0

3 years ago

Which Function has the graph below?

valentinak56 [21]

Answer:

Step-by-step explanation:

The general rule for the quadratic function is

$y=ax^2+bx+c$

From the graph you can see that the curve passes through the points (2,4), (1,7) and (3,7), so

$y(2)=4\Rightarrow 4=a\cdot 2^2+b\cdot 2+c\\ \\y(1)=7\Rightarrow 7=a\cdot 1^2+b\cdot 1+c\\ \\y(3)=7\Rightarrow 7=a\cdot 3^2+b\cdot 3+c$

We get the system of three equations:

$\left\{\begin{array}{l}4a+2b+c=4\\ \\a+b+c=7\\ \\9a+3b+c=7\end{array}\right.$

Subtract these equations:

$\left\{\begin{array}{l}4a+2b+c-a-b-c=4-7\\ \\9a+3b+c-a-b-c=7-7\end{array}\right.\Rightarrow \left\{\begin{array}{l}3a+b=-3\\ \\8a+2b=0\end{array}\right.$