Idk how to do this im literally just learning it

Mark has 312 books in his bookcases. He has 11 times as many fiction books as nonfiction books. How many fiction books does Mark

tankabanditka [31]

With the information given we can wirte down 2 different equations where:
x = How many Fictoon books there are
A nd y = How many non-fiction books there are :
#1) x + y = 312
( The total of the books is 312 )

#2) x = 11y
(He has 11 times as many firction books as he has non-ficton books)

Now what we need to do is to isolate one the variables ( x or y ) , get its value and apply to one the equations to get the other variable's value:
We can do that by the property of substitution:

If x = 11y
then x + y = (11y) + y = 12y

If x + y = 312
and x + y = 12y
then 12y = 312

Now with the equation 12y = 312 , we can isolate y by dividing both sides of the equation by 12 :
12/12y = 312/12
y = 26
What that means : Mark has 26 non-fictional books.

Now that we have the value of y , we can find the value of x by plugging y to one of the equations :

x + y = 312
or
x = 7y
( I will do both , but you dont need to )

x + y = 312
Plugin 26 for y :
x + 26 = 312

Shift 26 to the other side of the equation by subtracting both sides of the equation by 26:
x + 26 - 26 = 312 - 26
26 - 26 cancel out , so we end up with :
x = 286

Second Equation :
x = 11y
Plugin 26 for y:
x = 11 × 26

x = 286

Awnser : Mark has 286 fictoon books and 26 non-fiction !

I hope you understood my brief explanation. And please consider marking this awnser as Branliest. Thank you ! :)

5 0

4 years ago

A rectangle. one side is 2x + 7 and the other is x+3

saveliy_v [14]

$\large{\green}\fcolorbox{purple}{pink}{\bf{\underline{\red{\color{red}Answer}}}}$

6x + 20

Step-by-step explanation:

To find :-

Perimeter of rectangle

Given :-

Length = 2x + 7

Breadth/width = x + 3

Solution :-

We know that

$\mathfrak {perimeter \: of \: rectangle =2(length + breadth) }$

Now we will substitute the values of length and breadth

$\sf \longmapsto perimeter = 2 \{(2x + 7) + (x + 3) \} \\ \\ \\ \sf \longmapsto perimeter = 2 \{3x + 10 \} \\ \\ \\ \sf \longmapsto perimeter = 6x + 20$

6 0

2 years ago

A health statistics agency in a certain country tracks the number of adults who have health insurance. Suppose according to the

Nana76 [90]

Answer:

a) There is a 15.3% probability that a randomly selected person in this country is 65 or older.

b) Given that a person in this country is uninsured, there is a 2.2% probability that the person is 65 or older.

Step-by-step explanation:

We have these following percentages:

5.3% of those under the age of 18, 12.6% of those ages 18–64, and 1.3% of those 65 and older do not have health insurance.

22.6% of people in the county are under age 18, and 62.1% are ages 18–64.

(a) What is the probability that a randomly selected person in this country is 65 or older?

22.6% are under 18

62.10% are 18-64

The rest are above 65

So

100% - (22.6% + 62.10%) = 15.3%

There is a 15.3% probability that a randomly selected person in this country is 65 or older.

b) Given that a person in this country is uninsured, what is the probability that the person is 65 or older?

This can be formulated as the following problem:

What is the probability of B happening, knowing that A has happened.

It can be calculated by the following formula

$P = \frac{P(B).P(A/B)}{P(A)}$

Where P(B) is the probability of B happening, P(A/B) is the probability of A happening knowing that B happened and P(A) is the probability of A happening.

So, what is the probability that a person is 65 and older, given that the person is uninsured.

P(B) is the probability that a person is 65 and older. From a), we have that $P(B) = 0.153$

P(A/B) is the probability is uninsured, given that that person is 65 and older. So $P(A/B) = 0.013$

P(A) is the probability that a person is uninsured. That is the sum of 5.3% of 22.6%, 12.6% of 62.1% and 1.3% of 15.3%. So:

$P(A) = 0.053*(0.226) + 0.126*(0.621) + 0.013*(0.153) = 0.0922$

So

$P = \frac{P(B).P(A/B)}{P(A)} = \frac{0.153*0.013}{0.0922} = 0.022$

Given that a person in this country is uninsured, there is a 2.2% probability that the person is 65 or older.

6 0

3 years ago

The integer -1 is part of the solution set of x > -2. True False

Mumz [18]

The answer is True.
The answer is True.

3 0

3 years ago

25−2(5+4x)

ExtremeBDS [4]

Step-by-step explanation:

25 - 2(5 + 4x)

= 25 - 10 - 8x (Distributive Property)

= 15 - 8x.

3 0

3 years ago