Answer:(125-81.25)/125 = 0.35 = 35%
Step-by-step explanation:
 
        
             
        
        
        
Answer:  -a2 - 2ab - b2 + 25  = 
  -1 • (a2 + 2ab + b2 - 25) 
Final result :
  -a2 - 2ab - b2 + 25
Step-by-step explanation:
 
        
             
        
        
        
Given is the function for number of adults who visit fair at day 'd' after its opening, a(d) = −0.3d² + 4d + 9.
Given is the function for number of children who visit fair at day 'd' after its opening, c(d) = −0.2d² + 5d + 11.  
Any function f(d) to find excess of children more than adults can be written as follows :-  
f(d) = c(d) - a(d).
⇒ f(d) = (−0.2d² + 5d + 11) - (−0.3d² + 4d + 9)
⇒ f(d) = -0.2d² + 0.3d² + 5d - 4d + 11 - 9
⇒ f(d) = 0.1d² + d + 2
 
        
                    
             
        
        
        
Answer:
54 minutes 
Step-by-step explanation:
From the question, we are given;
- A room with dimensions 5.2 m by 4.3 m by 2.9 m
 - The exchange air rate is 1200 L/min 
 
We are required to determine the time taken to exchange the air in the room;
First we are going to determine the volume of the room;
Volume of the room = length × width × height 
                                   = 5.2 m × 4.3 m × 2.9 m
                                   = 64.844 m³
Then we should know, that 1 m³ = 1000 L
Therefore, we can convert the volume of the room into L
 = 64.844 m³ × 1000 L
= 64,844 L
But, the rate is 1200 L/min 
Thus, time = Volume ÷ rate 
                   = 64,844 L ÷ 1200 L/min 
                    = 54.0367 minutes 
                    = 54 minutes 
Therefore, it would take approximately 54 minutes