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3 years ago

Nick is solving the equation 3x^2=20-7x with the quadratic formula

Mathematics

1 answer:

krek1111 [17]3 years ago

6 0

Answer:

C. a = 3

b = 7

c = -20

Step-by-step explanation:

x = -b+/- (sq) b^2 - 4ac.

Well the way to plug the numbers in is by using this equation: Ax^2 + Bx + C = 0

S if you use your equation : 3x^2 = 20 - 7x

First you have to move everything to one side.

So it'll look like this:

3x^2 = 20 - 7x

-20 -20

3x^2 - 20 = -7x

+7x +7x

3x^2 - 20 + 7x = 0

don't forget that... Ax^2 +Bx+ C= 0

3 = A

7 = B

-20 = C

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Accuracy in taking orders at a drive-through window is important for fast-food chains. Periodically, QSR Magazine publishes "The

pav-90 [236]

Answer:

a) 0.7412 = 74.12% probability that all the three orders will be filled correctly.

b) 0.0009 = 0.09% probability that none of the three will be filled correctly

c) 0.0245 = 2.45% probability that at least one of the three will be filled correctly.

d) 0.9991 = 99.91% probability that at least one of the three will be filled correctly

e) 0.0082 = 0.82% probability that only your order will be filled correctly

Step-by-step explanation:

For each order, there are only two possible outcomes. Either it is filled correctly, or it is not. Orders are independent. This means that we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

The percentage of orders filled correctly at Burger King was approximately 90.5%.

This means that $p = 0.905$

You and 2 friends:

So 3 people in total, which means that $n = 3$

a. What is the probability that all the three orders will be filled correctly?

This is P(X = 3).

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 3) = C_{3,3}.(0.905)^{3}.(0.095)^{0} = 0.7412$

0.7412 = 74.12% probability that all the three orders will be filled correctly.

b. What is the probability that none of the three will be filled correctly?

This is P(X = 0).

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{3,0}.(0.905)^{0}.(0.095)^{3} = 0.0009$

0.0009 = 0.09% probability that none of the three will be filled correctly.

c. What is the probability that one of the three will be filled correctly?

This is P(X = 1).

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 1) = C_{3,1}.(0.905)^{1}.(0.095)^{2} = 0.0245$

0.0245 = 2.45% probability that at least one of the three will be filled correctly.

d. What is the probability that at least one of the three will be filled correctly?

This is

$P(X \geq 1) = 1 - P(X = 0)$

With what we found in b:

$P(X \geq 1) = 1 - P(X = 0) = 1 - 0.0009 = 0.9991$

0.9991 = 99.91% probability that at least one of the three will be filled correctly.

e. What is the probability that only your order will be filled correctly?

Yours correctly with 90.5% probability, the other 2 wrong, each with 9.5% probability. So

$p = 0.905*0.095*0.095 = 0.0082$

0.0082 = 0.82% probability that only your order will be filled correctly

7 0

3 years ago

Herman is standing on a ladder that is partly in a hole.He starts out on a rung that is 6 feet under ground ,climbs up 14 feet,t

fomenos

Well lets try using negatives and positives, negatives for underground positives for above. -6 + 14 = 8 then 8 - 11 = -3. When Herman finally stops climbing he is 3 feet below ground level.

5 0

3 years ago

Read 2 more answers

A t-shirt increased in price by 1/4. After the increase it was £20. What was the original price of the t-shirt?

Licemer1 [7]

Answer:

£16

the t-shirt increased by 0.25. let's convert that to percentage

therefore it increased by 25%

By using cross multiplication we can write as follows:

125%=£20

100%=£ x