Answer:
a) 9 km
b) 18 km
c) She runs at a constant speed of 9 km/h 
Step-by-step explanation:
 
        
             
        
        
        
The correct answer would be
A football pass of 9 yards
        
             
        
        
        
Answer:
two real, unequal roots
Step-by-step explanation:
y is definied as y = 3x - 1.  Substitute 3x - 1 for y in xy = 9, obtaining:
x(3x - 1) = 9.  Then:
3x^2 - x - 9 = 0.  In this quadratic, the coefficients are a = 3, b = -1 and c = -9.
Calculating the discriminant b^2 - 4ac, we get (-1)^2 - 4(3)(-9), or 1 + 108, or 109.  Because the discriminant is positive, we have two real, unequal roots.
 
        
             
        
        
        
Answer:
1.53
Step-by-step explanation:
because 21 minus 19.47= 1.53
 
        
                    
             
        
        
        
Answer:
0
Step-by-step explanation: