It's 93.
simple calculate it by:
(76+68+83+x)/4=80
then 73*5-(67+75+73+69)=x
where x here is the grade needed to reach an av. of 80. 4 is the number of tests.
*common answer*
Answer:
1: 3
Step-by-step explanation:
3:9
divide both sides by 3
1: 3
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;

Answer:
X= -5
Step-by-step explanation:
y varies directly with x,
so y=kx
-34=k×2
k= -17
85= -17× X
X= -5