Let
Present age of Sana = s
Present age of Mona = m 
Sana is senior to Mona by 18 years
s=m+18............(1) 
After 6 years 
Sana will be = s+6
Mona will be = m+6 
Then 
Sana will be twice as old as Mona
(s+6)=2(m+6)
s+6=2m+12
s=2m+12-6
s=2m+6.............(2)
Put the value of s from (2) to (1)
2m+6=m+18
2m-m=18-6
m=12
Put the value of m in (1)
s=m+18
s=12+18
s=30 
Present age of Sana = s = 30 years old
Present age of Mona = m = 12 years old
        
             
        
        
        
Answer:
(2x + y)(2x - y)
Step-by-step explanation:
1. Simplify the square 4x²:
(2x)² - y²
2. Apple the difference of two squares formula <em>x² - y² = (x + y)(x - y)</em>:
(2x + y)(2x - y)
hope this helps!
 
        
             
        
        
        
Answer:
640
Step-by-step explanation:
22 x 28 = 616
4 x 6 = 24 
616 + 24 = 640 fit
 
        
             
        
        
        
There would be a group of 12 and a group of 41
        
             
        
        
        
Answer: it is the one your cursor is on 
Step-by-step explanation:
I just put it in a calculator and it showed me