Answer:
7. 
8. l=11cm and w=7 cm
9. 
10. 
Step-by-step explanation:
Question 7.
The given expression is:

Expand the parenthesis using the distributive property:

Group similar terms:

Simplify

Divide both sides by -10

Question 8:
Let the width of the rectangle be;
The length of the rectangle is 
The perimeter is given as: 
Given that the perimeter P=36, then:
![36=2[(w+4)+w)]](https://tex.z-dn.net/?f=36%3D2%5B%28w%2B4%29%2Bw%29%5D)

Divide both sides by 2:

Subtract 4 from both sides:



The dimensions of the rectangle is: w=7 cm and l=7+4=11cm
Question 9
Let the number be x.
"5 fewer than the number" is written as 
"5 fewer than a number is at least 12" becomes

Question 10:
Let the number be x.
The quotient of a number and 3 is written as:

The quotient of a number and 3 is no more than 15 is written as;

Step-by-step explanation:
The water level is 8 feet below your dock.
The tide goes out, and the water level lowers
2 foot. A storm surge comes in, and the
water level rises 3 feet. Write an addition
expression to find the new water level.
Answer:
New Cost of item is 
Step-by-step explanation:
Given:
Original Cost of item = 
Item was marked down by 
To Calculate Cost after
marked down we need to multiply original cost by 50 and then divide by hundred.
Cost after marked down = 
Now New cost of the item is calculated by Subtracting Cost after
marked down by Original Cost of item.
New cost of the item = 
Answer:
1.165.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
In this problem, we have that:
. So


So the correct answer is:
1.165.
Answer:
Number of apartment = 9
Step-by-step explanation:
Given the ANOVA result :
ANOVA ____ df ____ SS
Regression __ 1 ___ 41587.1
Residual ____ 7 ___
Total _______ 8 __ 51984.5
Number of apartment building in sample (n) :
Degree of freedom (df) = n - 1
The degree of freedom = total = 8
Hence,
8 = n - 1
8 + 1 = n - 1 + 1
9 = n
Hence, number of apartment building in sample = 9