All categories

3 years ago

Find the value of two numbers if their sum is 23 and their difference is 3.

Mathematics

1 answer:

Yakvenalex [24]3 years ago

3 0

x+y=23

x-y=5

First, add the equations.

2x=28

x=14

Then...

14+y=23

y=9

Therefore the answer is...

x=14 y=9

You might be interested in

I need help

Julli [10]

Answer:

<h2>Solution :-</h2>

Radius is 3

Height is 2

So,

Volume = πr²h

Volume = 3.14 × (3)² × 2

Volume = 3.14 × 9 × 2

Volume = 3.14 × 18

Volume = 56.5 units²

5 0

2 years ago

Read 2 more answers

What is the inverse of f(x)=2x-6

saveliy_v [14]

Answer:

The inverse is 1/2x +3

Step-by-step explanation:

f(x) = 2x-6

y = 2x-6

Exchange x and y

x =2y-6

Solve for y

x+6 =2y

Divide by 2

1/2x +3 = y

The inverse is 1/2x +3

7 0

2 years ago

Farmer Green sent his two children out to count the hens and sheep. His daughter counted 40 hens, and his son counted 100 legs.

xz_007 [3.2K]

Answer:

40 hens, 5 sheep

Step-by-step explanation:

40 x 2 = 80 (hens have 2 legs)

100 - 80 = 20 ----> 20 legs left for sheep,, sheep have 4 legs

20/4 = 5 so there are 5 sheep

7 0

2 years ago

Read 2 more answers

An SRS of 350 high school seniors gained an average of x¯=21 points in their second attempt at the SAT Mathematics exam. Assume

Lynna [10]

Answer:

a) $21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

b) $ME=2.58\frac{52}{\sqrt{350}}=7.17$

c) $ME=2.58\frac{52}{\sqrt{100}}=13.42$

d) D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Part a

$\bar X=21$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=52$ represent the population standard deviation

n=350 represent the sample size

99% confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$