Question:
Solution:
Let the following equation:
![\sqrt[]{12-x}=\text{ x}](https://tex.z-dn.net/?f=%5Csqrt%5B%5D%7B12-x%7D%3D%5Ctext%7B%20x%7D)
this is equivalent to:
![(\sqrt[]{12-x})^2=x^2](https://tex.z-dn.net/?f=%28%5Csqrt%5B%5D%7B12-x%7D%29%5E2%3Dx%5E2)
this is equivalent to:

this is equivalent to:

thus, we can conclude that
x= 3.
Answer:
She will get 12 books from the store
Step-by-step explanation:
We can use ratio's to solve
2 books out x books out
------------------- =-----------------------------
3 books in 18 books in from Val
Using cross products
2 * 18 = 3 *x
Divide each side by 3
2*18 /3 = 3x/3
2*6 = x
12 =x
She will get 12 books from the store
Ebony kept her bank account open for only 3 weeks, and the graph shows the entire 3 weeks. During that time,her greatest balance was $400
Answer:
Function for given situation is : 
Value of computer after 4 years = $720.3.
Step-by-step explanation:
Given that the value of a $3000 computer decreases about 30% each year. Now we need to write a function for the computers value V(t). then we need to find about how much will the computer be worth in 4 years.
It clearly says that value decreases so that means function represents decay.
For decay we use formula:

where P=initial value = $3000,
r= rate of decrease =30% = 0.30
t= number of years
A=V(t) = future value
so the required function is 
or 
Now plug t=4 years to get the value of computer after 4 years.


Hence final answer is $720.3.
Option D. 2(n + 9) is the right answer
Step-by-step explanation:
The word problems are converted into mathematical problems to solve simply.
for the given problem
"two times the sum of a number and 9"
Let n be a number then
when there is and between two things they are performed first then next operation is performed so
the sum of a number and 9

Then
two times the sum of a number and 9

Hence,
Option D. 2(n + 9) is the right answer
Keywords: Mathematical notation
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