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3 years ago

Solve 2x2 + x − 4 = 0. x^2 + x+ = 0

Mathematics

2 answers:

denis23 [38]3 years ago

6 0

Answer:

1/2 -2

Step-by-step explanation:

alisha [4.7K]3 years ago

3 0

Kate: Please, for clarity, use " ^ " to denote exponentiation: 2x^2 + x − 4 = 0

And please include the instructions.

2x^2 + x − 4 = 0 can be re-written: 2(x^2 + (1/2)x - 2) = 0

Dividing both sides by 2 results in x^2 + (1/2)x - 2 = 0

Let's "complete the square:" x^2 + (1/2)x + (1/4)^2 - (1/4)^2 = 0

Then (x+(1/4))^2 = (1/4)^2

Taking the sqrt of both sides: x+1/4 = plus or minus 1/4

Solving for x: x = -1/4 plus or minus 1/4

Solving for x (continued): x = 0 and x = -1/2

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g Which of the following is not appropriate to use the t-confidence interval for . a. The sample is based on a simple random sam

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Answer:

d. The population standard deviation is known.

Step-by-step explanation:

T-distribution or Z-distribution, which to use?

If we have the population standard deviation is known, we use the z-distribution.

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2 years ago

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vovikov84 [41]

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3 years ago

A local carpet company has been hired to carpet a planetarium which is in the shape of a circle. If the radius of the planetariu

dem82 [27]

We are given radius = 6 yards

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2 years ago

A production process is known to produce a particular item in such a way that 5 percent of these are defective. If two items are

IRINA_888 [86]

Answer:

0.0025 = 0.25% probability that both are defective

Step-by-step explanation:

For each item, there are only two possible outcomes. Either they are defective, or they are not. Items are independent of each other. So 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.

5 percent of these are defective.

This means that $p = 0.05$

If two items are randomly selected as they come off the production line, what is the probability that both are defective

This is P(X = 2) when n = 2. So

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

$P(X = 2) = C_{2,2}.(0.05)^{2}.(0.95)^{0} = 0.0025$

0.0025 = 0.25% probability that both are defective

4 0

2 years ago

If P->q is true and q->r is true them the conclusión of p->r is also true this is called?

tino4ka555 [31]

Answer:

This is called transitivity property

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3 years ago

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