Just subtract the year we’re in now. 2021-30=1991
2021-40=1981
Mr. A- 1991
Mr. B- 1981
        
             
        
        
        
I will assume you mistyped this question. For y = -1/16x^2 + 4x + 3, the answers to this question are
a) 3 feet
b) 67 feet
c) 64.741 feet
For a) we note that at x = 0, that is the instant where the ball leaves the hand. y(0) = 0.
For b), we find the vertex of y = -1/16x^2 + 4x + 3
                               y = -1/16x^2 + 4x + 3
                               y = -1/16(x^2 - 64x) + 3
                               y = -1/16(x^2 - 64x + 1024 - 1024) + 3
                               y = -1/16((x-32)^2 - 1024) + 3
                               y = -1/16(x-32)^2 + 64 + 3
                               y = -1/16(x-32)^2 + 67
The vertex is at (32,67) so 67 is the maximum height.
For c), we find the x-intercepts with the quadratic formula on 
y = -1/16x^2 + 4x + 3=0:
                     x = [ -b ± √b^2 - 4ac ] / (2a)<span>
                     x = [ -4 ± √4^2 - 4(-1/16)(3) ] / (2(-1/16))    
                     x = -0.741, 64.741
Only the positive solution, so 64.741 feet         </span>
        
                    
             
        
        
        
A carpenter wants you to find the surface area of a shelf top. The length of the shelf is 3/4 m and the depth is 1/8 m.
        
             
        
        
        
Answer: 10.16 centimeters are in 4 inchs
Step-by-step explanation:
 
        
             
        
        
        
Answer:x= 5
Step-by-step explanation:
5x-12=63
>5x=63+12=75
>x=75÷5
>x=15