Answer:
It takes 1 seconds for push-ups and 3 seconds for sit-ups for Mei to do exercise.
Step-by-step explanation:
Given:
Let the time taken for push-ups be 'x'.
Let the time taken for sit-ups be 'y'.
Now Given:
17 push-ups and 6 sit-ups, it takes a total of 35 seconds.
So we can say that;

Also Given:
41 seconds to do 20 push-ups and 7 sit-ups.
so we can say that;

Now Multiplying equation 1 by 7 we get;

Now Multiplying equation 2 by 6 we get;

Now Subtracting equation 3 from equation 4 we get;

Now substituting the value of x in equation 1 we get;

Hence It takes 1 seconds for push-ups and 3 seconds for sit-ups for Mei to do exercise.
 
        
             
        
        
        
i think its 84 miles in 7 days 
 
        
             
        
        
        
Answer:
C.
Step-by-step explanation:
A complementary angle is an angle at 90 degrees and is formed by 2 angles.
 
        
             
        
        
        
Answer:
20a³
Step-by-step explanation:
Simply multiply:
-5(-4) = 20
-a(-a)(a) = a²(a) = a³
20a³
 
        
                    
             
        
        
        
Use proportion, so multiply 100 by 75, then divide it by 30 and that's your answer.....250