Answer:
C. φ
Step-by-step explanation:

Thus  can replace x
 can replace x
 
        
             
        
        
        
It takes 0.15625 minutes to paint 1 square feet
<em><u>Solution:</u></em>
Given that, I can paint 96 sq ft in 15 minutes
To find: Time taken to paint 1 square feet
From given,
96 square feet is painted in 15 minutes
Let "x" be the time taken to paint 1 square feet
Then, we can say,
96 square feet = 15 minutes
1 square feet = x minutes
This forms a proportion and we can solve the sum by cross multiplying

Thus it takes 0.15625 minutes to paint 1 square feet
 
        
             
        
        
        
Answer:
D)
Step-by-step explanation:
f(x) = x^2 -14x -72
0=x^2 - 14x-72
0=x^2 - 18x+4x-72
0=x(x-18)+4(x-18)
0=(x-18)(x+4)
x-18=0 or x+4=0
x1=18 or x2=-4
asis of symmetry: x=(x1+x2)/2
x=(18+(-4))/2
x=14/2
x=7