dillon is planning to save 1/2 of the 5$ that he has earned which expression is not equivalent to 1/2 of 5

Find the quadratic function ..<br><br> 3x2 - y2 = 9<br><br> x2 + 2y2 = 38

ruslelena [56]

Answer:

Step-by-step explanation:

3x2 - y2 = 9.........(1)

x2 + 2y2 = 38......(2)

Let x^2 = a and y^2 = b

:- the two equations becomes

3a - b = 9..........(3)

a + 2b = 38.......(4)

Multiplying (4) by 3

3a + 6b = 114........(5)

Substracting (3) from (5)

3a - 3a + 6b - (-b) = 114 - 9

6b +b = 105

7b = 105

b = 105/7

b = 15

And 3a - b = 9 putting b = 15

3a - 15 = 9

3a = 15+9

3a = 24

a = 24/3

a = 8

And

x^2 = a

x^2 = 8

x = √8

x = √(4×2)

x = 2√2

Also y^2 = b

y^2 = 15

y = √15

6 0

2 years ago

* Show steps

Mila [183]

Step-by-step explanation:

18 seconds to hour

18÷3600= 0.005 hour

accelerstion= velocity÷ time

60 mph÷ 0.005 = 12,000m/h^2

3 0

2 years ago

What is the slope intercept form for this graph ? Please answer !!

Dmitry_Shevchenko [17]

$y = \frac{3}{2} x + 3$

5 0

2 years ago

Read 2 more answers

Need help with #11. The answer is about 13.86 years but show work please.

tangare [24]

Answer:

13.86

Step-by-step explanation:

formula for cont. compounding interest is

Amount = Principal * e^rt

in this case the principal is 5000, and the amount is 10000 (double). the rate is 5% or 0.05. and t is what we are solving for.

sub in to get:

10000 = 5000e^0.05t

2 = e^0.05t

now convert to log form.

ln 2 = 0.05t

ln 2 / 0.05 = t

punch that into your calculator and you get 13.86 years

6 0

3 years ago

To estimate the mean height μ of male students on your campus,you will measure an SRS of students. You know from government data

nexus9112 [7]

Answer:

a) $\sigma = 0.167$

b) We need a sample of at least 282 young men.

Step-by-step explanation:

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by

$Z = \frac{X - \mu}{\sigma}$

This Zscore is how many standard deviations the value of the measure X is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

(a) What standard deviation must x have so that 99.7% of allsamples give an x within one-half inch of μ?

To solve this problem, we use the 68-95-99.7 rule. This rule states that:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviations of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we want 99.7% of all samples give X within one-half inch of $\mu$ . So $X - \mu = 0.5$ must have $Z = 3$ and $X - \mu = -0.5$ must have $Z = -3$ .

So

$Z = \frac{X - \mu}{\sigma}$

$3 = \frac{0.5}{\sigma}$

$3\sigma = 0.5$

$\sigma = \frac{0.5}{3}$

$\sigma = 0.167$

(b) How large an SRS do you need to reduce the standard deviationof x to the value you found in part (a)?

You know from government data that heights of young men are approximately Normal with standard deviation about 2.8 inches. This means that $\sigma = 2.8$