Answer:
2+4 + 0+ 1 = $7
Step-by-step explanation:
 
        
             
        
        
        
Answer: (a) x + 2y = -1  and  3x + y = 1
<u>Step-by-step explanation:</u>
I am not sure what the purpose was for the colored lines but I included them on the graph (below).
 
        
                    
             
        
        
        
The brain is about 1500kg when your about the age of fifteen
        
             
        
        
        
For slope m and point (x₁, y₁), the point-slope equation of the line can be written as
  y -y₁ = m(x -x₁)
You have m = -4 and (x₁, y₁) = (4, -9), so the equation of your line is
  D. y+9 = -4(x-4)