The axis of symmetry is at x = -3. 
This can be found by looking at the basic form of vertex form: 
y = (x - h)^2 + k
In this basic form the vertex is (h, k). By looking at what is plugged into the equation, it is clear that h = -3 and k = -4. This means the vertex is at (-3, -4). 
It is a fact that the axis of symmetry is a vertical line of x = (vertex value of x). So we can determine that the axis of symmetry is at x = -3 
 
        
             
        
        
        
1. Eyeballing the data, the best fit will be pretty close to a line between the leftmost point and the rightmost point.
We estimate those points as (4,220) and (28,470)
The point point form for a line joining (a,b) and (c,d) is
(c-a)(y-b) = (d-b)(x-a)
(28 - 4)(y - 220) = (470 - 220)(x - 4)
24(y - 220) = 250(x-4)
24y - 5280 = 250x - 1000
24y = 250 x + 4280
y = (250/24) x+ (4280/24)
Approximately that's,
y = 10.4 x + 178
Answer: 4th choice, 10.4x + 180
2. For 48 wheelbarrows,
y = 10.4(48)+180 = 679.2
Answer: 679.2 liters of sand
 
        
             
        
        
        
Answer: is there suposed to be a symbol between the 2x and the 2?
 
        
             
        
        
        
Answer: Usually the formula for the volume of a prism is V=b(h)—> In words, Volume equals base times height. This means the height 10 would replace h. —> V=b(10). Next we want to find the B in the forumla. If you notice the question says that the base is 24 square centimeters. So our new formula is V=24(10). So option C, V=24x10 is the correct answer.