Answer:
There are total 30 books in the 5 feet high stack of books.
Step-by-step explanation:
The complete question is
Given, Each note book is 2 inches thick, How many notebooks do you think it would take to make a stack that is 5 feet high
Solution
Thickness of each book 
The total height of the book stack is
feet.
The number of books in the stack is equal to total height of the stack divided by the thickness of one book
Number of books in five feet high stack is

Hence, there are total 30 books in the 5 feet high stack of books.
Answer:
12 - x
Step-by-step explanation:
y = -x + 12
Replace x with y.
x = -y + 12
Solve for y, x = -y + 12
= 12 - x
Hope this helps, please mark brainliest if possible. :)
Answer:
D: 8,100π in²
Step-by-step explanation:
The formula for area of a circle is
A = πr²
The radius is squared, so if the radius or a new circle is 6 times larger (multiplied by 6), the difference in area will be 36 times greater. So the area is
225π(36) = 8,100π
Answer: she is NOT correct the answer should be X= 19
How?:
the equation was 5x = 95
the 5 and x is being multiplied the opposite of multiplication is dividing
so 95/5= 19
therefor x= 19 and NOT 90
Answer:
405
Step-by-step explanation:
To find sample size, use the following equation, where n = sample size, za/2 = the critical value, p = probability of success, q = probability of failure, and E = margin of error.

The values that are given are p = 0.84 and E = 0.03.
You can solve for the critical value which is equal to the z-score of (1 - confidence level)/2. Use the calculator function of invNorm to find the z-score. The value will given with a negative sign, but you can ignore that.
(1 - 0.9) = 0.1/2 = 0.05
invNorm(0.05, 0, 1) = 1.645
You can also solve for q which is 1 - p. For this problem q = 1 - 0.84 = 0.16
Plug the values into the equation and solve for n.

Round up to the next number, giving you 405.