The area of the square:

where "a" is a length of side.
Therefore:
Answer:
-4
Step-by-step explanation:
If a = -4 then you can eliminate hte -4x and 4x by adding them, you get 0x, so you eliminate the x variable
Answer:
15) 
16) 12 hours
Step-by-step explanation:
15) 
16) If Jim drove 168 mi in 4 hours, this means it takes him

this many hours to drive 1 mile. So if we multiply this by 504 mi:

6 1/10 because 3 3/5 equals 3 6/10 and 2 1/2 equals 2 5/10. 3 6/10 plus 2 5/10=6 1/10
Answer:
The surface is a cylindrical surface with radius 7 units
Step-by-step explanation:
The equation is properly written as:

The above equation takes the form 
Where 

and 


r = 7 units
The surface is a cylindrical surface with radius 7 units