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3 years ago

X + 5y = 8 -x + 2y = -1 How to solve this?

Mathematics

1 answer:

ira [324]3 years ago

4 0

Answer:

x+5y=8

-5 -5

----------

x=3

-x+2y=-1

-2 -2

------------

-x

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4/3 x+12=-4 hell please right answer get brainliest points and show work please

IrinaVladis [17]

Answer:

x = -12

Step-by-step explanation:

4/3x + 12 = - 4 (multiply 3 both side)

4x + 36 = - 12 (minus 36 both side)

4x + 0 = -12

4x = -12 - 36

4x = - 48 (divide both side)

4x ÷ 4 = x

-48 ÷ 4 = -12

Answer: x = -12

8 0

3 years ago

How do I solve number 10? I'm not sure if I did it right.

grandymaker [24]

No, you did it right

3 0

2 years ago

Boxes of raisins are labeled as containing 22 ounces. Following are the weights, in the ounces, of a sample of 12 boxes. It is r

ZanzabumX [31]

Answer:

A 90% confidence interval for the mean weight is [21.78 ounces, 21.98 ounces].

Step-by-step explanation:

We are given the weights, in the ounces, of a sample of 12 boxes below;

Weights (X): 21.88, 21.76, 22.14, 21.63, 21.81, 22.12, 21.97, 21.57, 21.75, 21.96, 22.20, 21.80.

Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean weight = $\frac{\sum X}{n}$ = 21.88 ounces

s = sample standard deviation = $\sqrt{\frac{\sum (X-\bar X)^{2} }{n-1} }$ = 0.201 ounces

n = sample of boxes = 12

$\mu$ = population mean weight

Here for constructing a 90% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation.

So, 90% confidence interval for the population mean, $\mu$ is ;

P(-1.796 < $t_1_1$ < 1.796) = 0.90 {As the critical value of t at 11 degrees of

freedom are -1.796 & 1.796 with P = 5%}

P(-1.796 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 1.796) = 0.90

P( $-1.796 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.796 \times {\frac{s}{\sqrt{n} } }$ ) = 0.90

P( $\bar X-1.796 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.796 \times {\frac{s}{\sqrt{n} } }$ ) = 0.90

90% confidence interval for $\mu$ = [ $\bar X-1.796 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+1.796 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $21.88-1.796 \times {\frac{0.201}{\sqrt{12} } }$ , $21.88+1.796 \times {\frac{0.201}{\sqrt{12} } }$ ]

= [21.78, 21.98]

Therefore, a 90% confidence interval for the mean weight is [21.78 ounces, 21.98 ounces].

8 0

2 years ago

How do u solve to get x?

Vedmedyk [2.9K]

Step-by-step explanation:

2^(2x) - 5(2^x) = -4

(2^x)^2 - 5(2^x) = -4

Substitute 2^x = z --> x = ln(z)/ln(2)

z^2 - 5z = -4

z^2 - 5z + 4 = 0

(z - 1)(z - 4) = 0

z = 1 --> x = ln(1)/ln(2) = 0

z = 4 --> x = ln(4)/ln(2) = 2

4 0

3 years ago

You post a survey to the school about favorite desserts. Of the 540 students at the school, 60 answered the survey. 15 students

makkiz [27]

Answer:

135

Step-by-step explanation:

1. 540/60=9

2.9×15=135

4 0

3 years ago