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pav-90 [236]
3 years ago
11

Which could be the first step in solving this system of equations by substitution?

Mathematics
1 answer:
Ainat [17]3 years ago
3 0

Answer:

The first step is to replace the y in y-x=15 with 7x (we can do this because the first equation tells us that they're equal)

solve and get

(2.5,17.5)

or x= 2.5 y=17.5

Step-by-step explanation:

The first step is to recognize that y=7x which means that we can just replace the y in the second equation with 7x

7x-x=15

6x=15

x=2.5

Then we can solve for y

y=7(2.5)

y=17.5

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Using the quadratic formula to solve x2 = 5 – x, what are the values of x?
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Answer:

x²=5-x

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[ax²+bx²+c=0]

∆=b²-4ac

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x=(-b±√∆)/2a

x=(-1±√21)/2

meaning:

x=(-1+√21)/2 or x=(-1-√21)/2

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In how many ways can you put seven marbles in different colors into four jars? Note that the jars may be empty.
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Answer:

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Step-by-step explanation:

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4 years ago
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Consider the following Excel regression of perceived sound quality as a function of price for 27 stereo speakers. Regression Sta
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Answer:

Kindly check explanation

Step-by-step explanation:

Given the following :

Regression

Statistics

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Standard Error 4.02545

Observations 27

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Stat - - - - lower 95% - - - upper 95%

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(A) No, At α = .05, the Coefficient of price is not significantly different from zero, because :

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B) the correlation Coefficient (r) :

Since ; r^2 = 0.01104

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Using :

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0.1051(√27-2) / √1 - 0.01104

0.5255 / 0.9944646

= 0.5284250

For a 2 tailed test: α = .025

t0. 025 = 2.060 and - 2.060

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Please rephrase the question.

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