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2 years ago

Which ordered pairs in the form (x, y) are solutions to the equation 3x – 4y = 21? Choose all answers that are correct.

Mathematics

2 answers:

EleoNora [17]2 years ago

6 0

<h2>Answer:</h2>

The ordered pair which are solution to the equation are:

B. (-1,-6)

C. (7,0)

D. (11,3)

<h2>Step-by-step explanation:</h2>

We are given a equation in terms of variables x and y as follows:

$3x-4y=21$

The ordered pair which are solutions to the equation are the points which when substituted to the equation satisfies the equation.

(-3,3)

i.e. we put x= -3 and y=3 we get:

$3\times (-3)-4\times 3=21\\\\i.e.\\\\-9-12=21\\\\i.e.\\\\-21=21$

which is not possible.

Hence, (-3,3) is not a solution to the equation.

(-1,-6)

we put x=-1 and y=-6 into the equation to get:

$3\times -1-4\times (-6)=21\\\\i.e.\\\\-3+24=21\\\\i.e.\\\\21=21$

Hence, (-1,-6) is a solution to the equation.

(7,0)

we put x=7 and y=0 in the equation.

i.e.

$3\times 7-4\times 0=21\\\\i.e.\\\\21-0=21\\\\i.e.\\\\21=21$

Hence, (7,0) is a solution to the equation.

(11,3)

we put x=11 and y=3 into the equation.

i.e.

$3\times 11-4\times 3=21\\\\i.e.\\\\33-12=21\\\\i.e.\\\\21=21$

Hence, (11,3) is a solution to the equation.

bekas [8.4K]2 years ago

5 0

A. (−3, 3)
<span>3x – 4y = 21
</span>3(-3) - 4(3) = 21
-21 = 21 >>>>> not equal

B. (−1, −6)
<span>3(-1) - 4(-6) = 21
</span>21 = 21 >>>>>>>>>>Equal

C. (7, 0)
<span>3(7) - 4(0) = 21
</span>21 = 21>>>>>>>>>>equal

D. (11, 3)
<span>3(11) - 4(3) = 21
</span>21 = 21 >>>>>>>>>equal

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1 year ago

A random sample of 250 students at a university finds that these students take a mean of 15.2 credit hours per quarter with a st

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Answer:

95% confidence interval for the mean credit hours taken by a student each quarter is [14.915 hours , 15.485 hours].

Step-by-step explanation:

We are given that a random sample of 250 students at a university finds that these students take a mean of 15.2 credit hours per quarter with a standard deviation of 2.3 credit hours.

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where, $\bar X$ = sample credit hours per quarter = 15.2 credit hours

s = sample standard deviation = 2.3 credit hours

n = sample of students = 250

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<em>Here for constructing 95% confidence interval we have used One-sample t test statistics as we know don't about population standard deviation.</em>

So, 95% confidence interval for the population mean, $\mu$ is ;

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P( $\bar X-1.96 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.96 \times {\frac{s}{\sqrt{n} } }$ ) = 0.95

<u><em>95% confidence interval for</em></u> $\mu$ = [ $\bar X-1.96 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+1.96 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $15.2-1.96 \times {\frac{2.3}{\sqrt{250} } }$ , $15.2+1.96 \times {\frac{2.3}{\sqrt{250} } }$ ]

= [14.915 hours , 15.485 hours]

Therefore, 95% confidence interval for the mean credit hours taken by a student each quarter is [14.915 hours , 15.485 hours].

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8 0

1 year ago

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<h2>Greetings!</h2>

Answer:

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First, we need to find the amount he was paid over the 35 weeks:

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So every week he is paid $25

The function has to start with 34, as that is the amount already in there, and as w is multiplying by 25, this can be written as 25w

So put these two together:

f(x) = 34 + 25w

<h2>Hope this helps!</h2>

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2 years ago

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Answer:

Step-by-step explanation:

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1 year ago