Answer:
No. 
Step-by-step explanation:
No, y=x²-6 is not a linear function. 
This is because all linear functions have the highest exponent of 1. Anything equation that has a variable raised to a power other than 1 is not linear. 
The equation provided as the highest exponent of 2. Thus, it's not linear. 
From the provided graph, we can also see that this is quadratic instead of linear. The graph is a parabola instead of a line. 
 
        
                    
             
        
        
        
So first of all we need to know that area is length times width
Area = L x W 
since we know the area is 42 and the length is 12 lets plug those in
42 = 12 x W 
now we dont know what W is yet but we can figure it out by dividing 42 by 12
42/12 = 3.5 
So W = 3.5!
but its asking for the perimeter and we know that perimeter is all of the sides of the rectangle added up. Heres a picture
   
       ___3.5___
      |                 |
      |                 |
 12 |                 |  12 
      |                 |
      ************
             3.5
see now we just add those all up together:)
12 + 12 + 3.5 + 3.5 = 31!!
so our perimeter is 31 inches:)
have a good one 
PICK ME BRAINLIEST!:D