Answer:
Step-by-step explanation:
Let x represent the number of 3-lb bags purchased. Then the total purchase was ...
   $2(8 -x) +$5.50(x) = $37
   16 +3.50x = 37 . . . . . . . . . divide by $, collect terms
   3.50x = 21 . . . . . . . . . . . . . subtract 16
   21/3.50 = x = 6 . . . . . . . . divide by the coefficient of x
You bought 6 3-lb bags of peanuts and 2 1-lb bags.
 
        
             
        
        
        
6 boys, ratio is boy:girl 2:3
        
             
        
        
        
Answer:
0.3
Step-by-step explanation:
0.8/y = 2 : 3/4
The value of y in the above expression can be obtained as follow:
0.8/y = 2 : 3/4
0.8/y = 2 ÷ 3/4
0.8/y = 2 × 4/3
0.8/y = 8/3
Cross multiply 
0.8 × 3 = y × 8
2.4 = 8y
Divide both side by the coefficient of y i.e 8
y = 2.4/8
y = 0.3
Thus, the value of y is 0.3