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;

Let the number be x
3x - 5 = 14
3x = 19
X = 6 1/3 or 6.333333...
3x=9 is C
4x+12 is A
X+1 is B
Answer:X/3X=3
We move all terms to the left:
X/3X-(3)=0
Domain of the equation: 3X!=0
X!=0/3
X!=0
X∈R
We multiply all the terms by the denominator
X-3*3X=0
Wy multiply elements
X-9X=0
We add all the numbers together, and all the variables
-8X=0
X=0/-8
X=0
Step-by-step explanation: