All categories

3 years ago

Solve the system by elimination please help me

Mathematics

1 answer:

castortr0y [4]3 years ago

4 0

Answer:

x = 3 and y = 7

Step-by-step explanation:

2x + y = 13

+ x - y = -4 (adding both equations)

3x - 0y = 9

3x = 9

x = 9/3

x = 3

now substituting

x - y = -4

3 - y = -4

- y = -4 - 3

- y = -7

y = 7 (the negative sign on both sides get canceled)

Therefore,

x = 3 and y = 7

Happy to help :)

You might be interested in

a family has five children. the probability of having a girl is 1/2. whats probability of having at leasr 4 girls g'

Dima020 [189]

Answer:

Probability of having at least 4 Girls

= 0.6875

Step-by-step explanation:

Probability of having at least 4 Girls is 1-probability of having exactly 3 girls

Total number of children= 5 = N

Probability of having a girl p = 0.5

Probability of not having a girl q= 0.5

X= 3

Probability of at least 4 girls is given by

Probability= NCX(p)^x(q)^(N-x)

Probability = 5C3(0.5)^3(0.5)^(5-3)

Probability = 5C3(0.5)^3(0.5)^2

Probability= 5!/3!2!(0.5)^3(0.5)^2

Probability= 10(0.125)(0.25)

Probability= 0.3125

Probability of having at least 4 Girls

= 1- 0.3125

= 0.6875

7 0

3 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

3 years ago

What is the answer to my problem

Nadya [2.5K]

Please provide more context for our brains to understand your problem (: thank you!

7 0

3 years ago

Erica solved the equation -5x - 25 = 78; her work is shown below. Identify the error and were it was made

Nata [24]

Answer:

Step-by-step explanation:

It's A because she subtracted a negative and that only make a bigger negative where she should have added

7 0

3 years ago

Line A Line B Or Line C Or D? Thanks to whoever helps (:

vova2212 [387]

Answer is B. It isn't going up or down on the y axis

8 0

4 years ago

Read 2 more answers