All categories

3 years ago

Which two points satisfy y=-x2(^)+2x+4 and x+y=4?

1 answer:

5 0

Use subtitution method to solve the problem.

First, change y to the value of x in order to find the exact value of x.
x + y = 4
y = 4 - x

Second, subtitute y with 4 - x from the first equation
y = -x² + 2x + 4
4 - x = -x² + 2x + 4
move all terms to the left side
x² - 2x - x + 4 - 4 = 0
x² - 3x = 0
x(x - 3) = 0
x = 0 or x = 3

Third, now we have 2 values of x. Find the value of y for each of x
For x = 0
y = 4 - x
y = 4 - 0
y = 4

For x = 3
y = 4 - x
y = 4 - 3
y = 1

The solution is (0,4) and (3,1). The answer is option b

You might be interested in

Please Help! I will give you a lot of points! (6.3)

Mandarinka [93]

Let x be the yearly salary of an architect. Then the yearly salary of a lawyer is 2x-20000.

We can build an equation now! x+(2x-20000)=211000, because the yearly salary of an architect plus the yearly salary of a lawyer is 211000.

We combine like terms to get 3x-20000=211000.

We add 20000 to both sides to get 3x=231000.

We divide both sides by 3 to get x=77000, so the average yearly salary of a lawyer is 77000.

Then, the average yearly salary of an architect is 2(77000)-20000=154000-20000=134000, so the average yearly salary of an architect is 134000.

8 0

3 years ago

The equation of function f is f(x)=-3/2x+120. the domain of function f is 0 greater than or equal to x greater than or equal to

tia_tia [17]

Answer:

nanklnvccvndm

Step-by-step explanation:

annsnnxnxnznakka

6 0

2 years ago

A machine has 12 identical components which function independently. The probability that a component will fail is 0.2. The machi

iogann1982 [59]

Answer:

$P(X>3) =1- P(X\leq 3) = 1-[P(X=0)+P(X=1) +P(X=2) +P(X=3)]$

And if we find the individual probabilities we got:

$P(X=0)=(12C0)(0.2)^0 (1-0.2)^{12-0}=0.0687$

$P(X=1)=(12C1)(0.2)^1 (1-0.2)^{12-1}=0.2062$

$P(X=2)=(12C2)(0.2)^2 (1-0.2)^{12-2}=0.2835$

$P(X=3)=(12C3)(0.2)^3 (1-0.2)^{12-3}=0.2362$

And if we replace we got:

$P(X>3) =1- P(X\leq 3) = 1-[0.0687+0.2062 +0.2835 +0.2362]=0.20543$

Step-by-step explanation:

Previous concepts

A Bernoulli trial is "a random experiment with exactly two possible outcomes, "success" and "failure", in which the probability of success is the same every time the experiment is conducted". And this experiment is a particular case of the binomial experiment.

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

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

The complement rule is a theorem that provides a connection between the probability of an event and the probability of the complement of the event. Lat A the event of interest and A' the complement. The rule is defined by: $P(A)+P(A') =1$

Solution to the problem

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=12, p=0.2)$

And we want to find this probability:

$P(X > 3)$

And we can use the complement rule and we got:

$P(X>3) =1- P(X\leq 3) = 1-[P(X=0)+P(X=1) +P(X=2) +P(X=3)]$

And if we find the individual probabilities we got:

$P(X=0)=(12C0)(0.2)^0 (1-0.2)^{12-0}=0.0687$

$P(X=1)=(12C1)(0.2)^1 (1-0.2)^{12-1}=0.2062$

$P(X=2)=(12C2)(0.2)^2 (1-0.2)^{12-2}=0.2835$

$P(X=3)=(12C3)(0.2)^3 (1-0.2)^{12-3}=0.2362$

And if we replace we got:

$P(X>3) =1- P(X\leq 3) = 1-[0.0687+0.2062 +0.2835 +0.2362]=0.20543$

4 0

3 years ago

Read 2 more answers

For a direct variation, describe how the constant variation affects whether y increases or decreases as x increases.

Nataly_w [17]

<span>A direct variation is of the form
y = kx
where k is the constant of variation

In most cases k is positive in which case
y increase in direct proportion to an increase in x
Example
k = 2
x = 1,       y = kx = 2(1)= 2
x = 3,       y = kx = 2(3) = 6

Occasionally k is negative in which case
y decreases in direct proportion to an increase in x
Example
k = -2
x = 1,       y = kx = (-2)(1) = -2
x = 3,       y = kx = (-2)(3) = -6
---------------------------

This is not to be confused with an indirect variation which is of the form
y = k/x
where k is the constant of variation
Example

When k is positive y decreases inversely as x increases
k = 2
x = 1,       y = k/x = 2/1 = 2
x = 3, y = k/x = 2/3 = 2/3

When k is negative y increases inversely as x increases
k = -2
x = 1,       y = k/x = -2/1 = -2
x = 3        y = k/x = -2/3 = -2/3</span>

8 0

3 years ago

What is 9/20+4/27 as a fraction

marusya05 [52]

In a fraction it’s =323/540 if u want the steps let me know

6 0

3 years ago

Read 2 more answers