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3 years ago

What are the solutions to this problem? (use the quadratic formula and i) -2x^2+5x-11=0

Mathematics

2 answers:

Sever21 [200]3 years ago

7 0

Step-by-step explanation:

The quadratic formula is:

$x = \frac{-b \pm\sqrt{b^2-4ac} }{2a}\\$

A, in this case, is -2.

B is 5

C is -11

x = $\frac{-5 \pm\sqrt{5^2-4(-2)(-11)} }{2(-2)}$

x = $\frac{-5\pm\sqrt{25 -88} }{-4}\\$

x = $\frac{-5\pm\sqrt{-63}}{-4}$

x = $\frac{-5+i\sqrt{63} }{-4}$ and $\frac{-5-i\sqrt{63} }{-4}$

We can break up the fraction to make it easier on our eyes

x = $\frac{5}{4}\pm\frac{i\sqrt{63} }{4}$

$\frac{\sqrt{63} }{4}$ ≈1.9843

x = $1.25 + 1.9843i\\1.25 - 1.9843i$

sergejj [24]3 years ago

6 0

Answer:

Step-by-step explanation:

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4(5x-3) equivalent to?

BlackZzzverrR [31]

Answer:

20x-12

Step-by-step explanation:

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3 years ago

To plan the budget for next year a college must update its estimate of the proportion of next year's freshmen class that will ne

Naily [24]

Answer:

Null hypothesis: $p\leq 0.35$

Alternative hypothesis: $p > 0.35$

$z=\frac{0.447 -0.35}{\sqrt{\frac{0.35(1-0.35)}{150}}}=2.491$

$p_v =P(z>2.491)=0.0064$

So the p value obtained was a very low value and using the significance level assumed $\alpha=0.05$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of applicants who request financial aid is significantly higher than 0.35

Step-by-step explanation:

Data given and notation

n=150 represent the random sample taken

X=67 represent the applicants who request financial aid

$\hat p=\frac{67}{150}=0.447$ estimated proportion of applicants who request financial aid

$p_o=0.35$ is the value that we want to test

$\alpha$ represent the significance level

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to test the claim that the true proportion of applicants who request financial aid is higher than 0.35.:

Null hypothesis: $p\leq 0.35$

Alternative hypothesis: $p > 0.35$

When we conduct a proportion test we need to use the z statistic, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.447 -0.35}{\sqrt{\frac{0.35(1-0.35)}{150}}}=2.491$

Statistical decision

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

The next step would be calculate the p value for this test.

Since is a right tailed test the p value would be:

$p_v =P(z>2.491)=0.0064$

5 0

3 years ago

What should be added to x^2 + 4 to get 2x^2 + 5

Art [367]

Answer:

x+1

Step-by-step explanation:

4 0

3 years ago

Explain the relationship between the legs and the hypotenuse of a right triangle.

KATRIN_1 [288]

Answer:

Step-by-step explanation:

a right triangle and hypotenuse consist of two legs. the two legs meet at a 90 degrees angle and the hypotenuse is the longest side of the right triangle

4 0

4 years ago

(-3,1) perpendicular to y=2/5x-4

miss Akunina [59]

(-3, 1) y = 2/5x - 4
x₁ y₁ slope (m) = 2/5x

Since the equation we are looking for is perpendicular to y = 2/5x - 4, we need to find the opposite reciprocal slope. We have to flip the slope upside down and turn it negative.

2/5 ⇒ 5/2 ⇒ -5/2

So far, we have the equation y = -5/2.

Now, we need to find the y intercept by plugging in the given point into point slope form, which is...

y - y₁ = m(x - x₁)

The subscripts in the y and x are just the x and y in (-3,1). They are just placeholders, not exponents.

y - 1 = -5/2(x + 3)
y - 1 = -5/2x - 15/2
+ 1 + 1
------------------------------
y = -5/2x - 13/2 ⇒ final equation

4 0

3 years ago