All categories

3 years ago

One number is seven more than three times another number. If the sum of the numbers is 15, find the numbers.

Mathematics

1 answer:

dimulka [17.4K]3 years ago

4 0

Answer:

2 and 13

Step-by-step explanation:

We can use systems of equations here to find both the numbers. Let's assume one of the numbers is $x$ and the other is $y$ .

We know that these numbers add up to 15, so $x + y = 15$ .

We also know that one of these numbers is 7 more than 3 times the other, so $x = 3y + 7$ .

We can now substitute the equation $x = 3y + 7$ into $x + y = 15$ .

$(3y + 7) + y = 15$

Combine like terms:

$4y + 7 = 15$

Subtract 7 from both sides:

$4y = 8$

Divide both sides by 4:

$y = 2$ .

Now that we know the value of $y$ , we can substitute it inside an equation to find $x$ . Let's substitute it inside $x + y = 15$ .

$x + 2 = 15\\\\x = 15-2\\\\x = 13$

So the two numbers are 2 and 13.

Hope this helped!

You might be interested in

Tamara is at the store buying pencils. There is a package with 4 pencils that costs $6 or a package with 5 pencils that costs $7

Mkey [24]

In order to determine the cost of each pencil we have to divide the total cost for the package of pencils by the number of pencils contained

For the 4 pencils box:

Cost per pencil = Total cost/number of pencils

Cost per pencil = 6/4 = 1.5

Similarly, for the 5 pencils package:

Cost per pencil = 7/5 = 1.4

As you can see, the $7 package is better to buy, because each pencil costs $1.4, then, option A is the correct answer

8 0

1 year ago

A meuseum added 18 painting to its collection in may. This is 20% of paintings the meuseum has in April. How many paintings did

Alexus [3.1K]

18 / x = 20 / 100

20x = 1800

x = 90

The museum had 90 paintings in April.

Hope this helps!! :)

5 0

3 years ago

A selective university advertises that 96% of its bachelor’s degree graduates have, on graduation day, a professional job offer

OLEGan [10]

Answer:

The probability is $P( p < 0.9207) = 0.0012556$

Step-by-step explanation:

From the question we are told

The population proportion is $p = 0.96$

The sample size is $n = 227$

The number of graduate who had job is k = 209

Generally given that the sample size is large enough (i.e n > 30) then the mean of this sampling distribution is

$\mu_x = p = 0.96$

Generally the standard deviation of this sampling distribution is

$\sigma = \sqrt{\frac{p (1 - p )}{n} }$

=> $\sigma = \sqrt{\frac{0.96 (1 - 0.96 )}{227} }$

=> $\sigma = 0.0130$

Generally the sample proportion is mathematically represented as

$\^ p = \frac{k}{n}$

=> $\^ p = \frac{209}{227}$

=> $\^ p = 0.9207$

Generally probability of obtaining a sample proportion as low as or lower than this, if the university’s claim is true, is mathematically represented as

$P( p < 0.9207) = P( \frac{\^ p - p }{\sigma } < \frac{0.9207 - 0.96}{0.0130 } )$

$\frac{\^ p - p}{\sigma } = Z (The \ standardized \ value\ of \ \^ p )$

$P( p < 0.9207) = P(Z< -3.022 )$

From the z table the area under the normal curve to the left corresponding to -3.022 is

$P(Z< -3.022 ) = 0.0012556$

=> $P( p < 0.9207) = 0.0012556$

6 0

3 years ago

What is the approximate volume of the sphere? Use 3.14 to approximate pi and round the answer to the nearest hundredth if necess

zvonat [6]

The answer is D. Hope this helped =)

3 0

3 years ago

-6 < -3; Divide both sides by -3 <br><br> here is another question prove how smart you are

o-na [289]

Answer:

2 > 1

Step-by-step explanation:

-6 < -3 to -6/-3 > -3/-3 to 2 > 1

When dividing or multiplying by a negative, flip the inequality sign.

3 0

3 years ago