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2 years ago

2x-y=3 ; 5x+2y=30 solve using elimination

Mathematics

1 answer:

Zigmanuir [339]2 years ago

4 0

Answer:

x = 4, y = 5

Step-by-step explanation:

$2x-y=3\\4x-2y=6$

so:

$4x - 2y = 6\\+ 5x + 2y = 30\\9x= 36\\x=4$

Substitute this into 2x - y = 3:

$8-y=3\\y = 5$

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It says that I need to find x for the missing angle in the equation.

Anuta_ua [19.1K]

Answer:

Could you possible elaborate on the question more?

4 0

3 years ago

Which is equivalent to RootIndex 3 StartRoot 8 EndRoot Superscript one-fourth x?

Nat2105 [25]

<h3>Answer: Choice C</h3>

RootIndex 12 StartRoot 8 EndRoot Superscript x

12th root of 8^x = (12th root of 8)^x

$\sqrt[12]{8^{x}} = \left(\sqrt[12]{8}\right)^{x}$

=========================================

Explanation:

The general rule is

$\sqrt[n]{x} = x^{1/n}$

so any nth root is the same as having a fractional exponent 1/n.

Using that rule we can say the cube root of 8 is equivalent to 8^(1/3)

$\sqrt[3]{8} = 8^{1/3}$

-----

Raising this to the power of (1/4)x will have us multiply the exponents of 1/3 and (1/4)x like so

(1/3)*(1/4)x = (1/12)x

In other words,

$\left(8^{1/3}\right)^{(1/4)x} = 8^{(1/3)*(1/4)x}$

$\left(8^{1/3}\right)^{(1/4)x} = 8^{(1/12)x}$

-----

From here, we rewrite the fractional exponent 1/12 as a 12th root. which leads us to this

$8^{(1/12)x} = \sqrt[12]{8^{x}}$

$8^{(1/12)x} = \left(\sqrt[12]{8}\right)^{x}$

4 0

2 years ago

Read 2 more answers

40 points and brainlyest to who ever answers this for me- please someone help me

mixer [17]

Answer:

9) A

10) B

11) A

12) D

13) C

14) A

15) C

16) D

17) E (not sure, can't see full choice)

18) B

19) C

Explanation:

Hope this is what you're looking for friend :)

6 0

2 years ago

Find each product mentally. show the steps you used.7 × 2.9

JulijaS [17]

Answer is 20.3 and the steps are:
1.) 7 x 9 = 63 move the six over the 2 leave the 3 down
2.) 7 x 2 = 14
3.) 14 + 6 = 20
4.) you have 203 but must bring the decimal down and it makes it: 20.3
I hope I helped and if you're confused please ask questions

6 0

3 years ago

Sarah claims that the thickness of the spearmint gum she produces is 7.5 one-hundredths of an inch. A quality control specialist

satela [25.4K]

Answer:

$t=\frac{7.55-7.5}{\frac{0.103}{\sqrt{10}}}=1.539$

$p_v =2*P(t_{(9)}>1.539)=0.158$

If we compare the p value and the significance level assumed $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis.

Step-by-step explanation:

Data given and notation

Data: 7.65, 7.60, 7.65, 7.7, 7.55, 7.55, 7.4, 7.4, 7.5, 7.5

We can begin calculating the sample mean given by:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

And the sample deviation given by:

$s=\sart{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

And we got:

$\bar X=7.55$ represent the sample mean

$s=0.103$ represent the sample standard deviation

$n=10$ sample size

$\mu_o =7.5$ represent the value that we want to test

$\alpha=0.05$ 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 conduct a hypothesis in order to check if the mean is equal to 7.5 or no, the system of hypothesis would be:

Null hypothesis: $\mu = 7.5$

Alternative hypothesis: $\mu \neq 7.5$

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic 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:

$t=\frac{7.55-7.5}{\frac{0.103}{\sqrt{10}}}=1.539$

P-value

The first step is calculate the degrees of freedom, on this case:

$df=n-1=10-1=9$

Since is a two sided test the p value would be:

$p_v =2*P(t_{(9)}>1.539)=0.158$

Conclusion

If we compare the p value and the significance level assumed $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis.

3 0

3 years ago