In this question, the first information that we get is that Kayla spent half of her weekly allowance in clothes. On cleaning the oven Kayla gets $4. Finally Kayla is left with $12. 
Let us assume that the weekly allowance of Kayla = x
Amount of allowance saved after buying clothes = x/2
 Then we can go for the equation
x/2 + 4 = 12
x + (4 * 2) = 12 * 2
x + 8 = 24
x = 24 -8
   = 16
So we can now see that the weekly allowance of Kayla is $16
        
             
        
        
        
Answer:
Step-by-step explanation:
- When 1 gallon is has been used  400 square feet of the wall will be paint 
- The unit rate is 400 square feet per gallon 
 
        
             
        
        
        
Answer:
x∈R
Step-by-step explanation:

2>0
The domain is all real numbers.
x∈R