To get the answer you need to find out how many miles she bikes in 10minutes. 
Divide 50minutes by 10 you get 5. Now you divide 10(miles) by 5 and you get 2. So it means that in 10minutes she bikes 2miles. Now you need to know how many miles she bikes in 90minutes so if she bikes 2 in 10 then because 90:10=9 you do 2*9=18. She can bike 18miles in 90minutes. :))
        
                    
             
        
        
        
Answer:
C 
Step-by-step explanation:
In the attached file
 
        
             
        
        
        
Answer:
10 days.
Step-by-step explanation:
to find what you multiply from 400 to get to 4000, you divide 4000 by 400, which is 10, plug that in, 400 pounds x 10 days = 4000 pounds.
 
        
                    
             
        
        
        
Answer:
x=5+b/2
Step-by-step explanation:
move all terms that dont contain x to the right, and solve
 
        
                    
             
        
        
        
Answer:
4x + 5y = 20
Step-by-step explanation:
4x + 5y = 20
5y = -4x + 20      (Subtract 4x to isolate 5y. Put the 4x in front of the 20)
y =  + 4         (Divide all by 5 to isolate y)
 + 4         (Divide all by 5 to isolate y)
And then it's done and in slope-intercept form
 or
        or  is greater than -1 but less than 0
 is greater than -1 but less than 0
I hope this helped :)