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3 years ago

Decide which part of the quadratic formula tells you whether the quadratic equation can be solved by factoring.

Mathematics

1 answer:

Artyom0805 [142]3 years ago

5 0

Answer:

b^2-4ac, the value of the discriminant is 4

Step-by-step explanation:

The part b^2-4ac called the discriminant will tell you how many solutions a particular equation has, after plugging in the values you can tell how many solutions and what type of solutions that equation has by looking at whether the result is positive and a perfect square, positive, zero, or negative. If the result is a positive perfect square, there will be two rational solutions; if the result is positive there will be two real zeros; if the result is zero, there is one real zero; if the result is negative, there will be two complex conjugates or imaginary terms.

To find the value of the discriminant plug in the values of the equation.

6^2-4(4)(2)=4

The value of the discriminant in this particular equation is a perfect square, that means that there are two rational solutions. Put simply, this equation is factorable.

4x^2 + 6x + 2 = 0

(x+1)(4x+2)=0

x=-1 or -1/2

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11. The preferred overall competition area in judo, including the mats, is a square with an area of 256 m2.

choli [55]

<span>a) We know that the correct answer will be the square root of 256 since the competition area is a square with an area of 256 meters. And since 10^2 = 100 which is less than 256, the answer has to be greater than 10. And since 20^2 = 400 which is greater than 256, the answer also has to be less than 20. Therefore the answer has to be between 10 and 20. b) The last digit has to be either a 4 or a 6. The units digit is the only digit that will contribute to the units digit of the square. And 0^2 = 0, 1^2 = 1, 2^2 = 4, 3^2 = 9, 4^2 = 16, 5^2 = 25, 6^2 = 36, 7^2 = 49, 8^2 = 64, 9^2 = 81. Of the 10 possible digits, only the values 4 and 6 have a square that has an units digit of 6. c) The square root of 256 based up (a) and (b) above has to be either 14, or 16. So the dimensions are either 14x14 meters or 16x16 meters.</span>

3 0

3 years ago

52,908 round to the nearest hundred.

IrinaVladis [17]

The hundredth is the 3rd number after the decimal place (so the 9). Look at the number before it and if it is 5 or above then round it to the next hundredth. In this case it is only a zero so we don't change the 9 just substitute it 0's. Therefore the answer is 52,900.

If you need further help let me know, hope this helped you.

6 0

3 years ago

What is the value of this expression?<br> 5x (8 – 3) + 2

ivolga24 [154]

Answer:

Step-by-step explanation:

5 x (8 - 3) +2

5 x (5) + 2

25 + 2

Hope that helps!

4 0

4 years ago

Read 2 more answers

A random sample of 121 automobiles traveling on an interstate showed an average speed of 73 mph. from past information, it is kn

tatiyna

121 is big enough to assume normality and not worry about the t distribution. By the 68-95-99.7 rule a 95% confidence interval includes plus or minus two standard deviations. So 95% of the cars will be in the mph range

$(73 - 2 \cdot 11, 73 + 2 \cdot 11) = (51,95)$

The question is a bit vague, but it seems we're being asked for the 95% confidence interval on the average of 121 cars. The 121 is a hint of course.

The standard deviation of the average is in general the standard deviation of the individual samples divided by the square root of n:

$\sigma = \dfrac{ 11}{\sqrt{121}} = 1$

So repeating our experiment of taking the average 121 cars over and over, we expect 95% of the averages to be in the mph range

$(73 - 2 \cdot 1, 73 + 2 \cdot 1) = (71,75)$

That's probably the answer they're looking for.

4 0

3 years ago

Minor surgery on horses under field conditions requires a reliable short-term anesthetic producing good muscle relaxation, minim

andreev551 [17]

Answer:

$p_v =P(t_{74}$

If we compare the p value and a significance level for example $\alpha=0.1$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so we can conclude that the true mean it's not significantly less than 20 min.

Step-by-step explanation:

Data given and notation

$\bar X=18.81$ represent the average lateral recumbency for the sample

$s=8.4$ represent the sample standard deviation

$n=75$ sample size

$\mu_o =20$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

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

State the null and alternative hypotheses.

We need to apply a left tailed test.

What are H0 and Ha for this study?

Null hypothesis: $\mu \geq 20$

Alternative hypothesis : $\mu < 20$

Compute the test statistic

The statistic for this case is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{18.81-20}{\frac{8.4}{\sqrt{75}}}=-1.227$

The degrees of freedom are given by:

$df=n-1=75-1=74$

Give the appropriate conclusion for the test

Since is a one side left tailed test the p value would be:

$p_v =P(t_{74}$

Conclusion

3 0

3 years ago