Answer:
Option A and B are correct
Step-by-step explanation:
We have to add here 
6x+5y=1.
6x-5y=7
sow e will get 12x=8 , x=8/12=2/3
Option A  is correct.
If We substract bottom from furst then
6x+5y=1
-6x+5y=-7
10y=-6
y=-6/10=-3/5
we put y=-3/5 in any equation and find x
6x+5(-3/5)=1
6x=4
x=4/6=2/3
So Option B also correct.
  
        
             
        
        
        
Answer:
39
Step-by-step explanation:
4 is once 7 is more than 5 so u have to add 1 number to the 8 so 8 will become 9 
 
        
             
        
        
        
Answer:
Step-by-step explanation:
1 1/2 = 3/2
 
        
             
        
        
        
If you would do this in whole number form, it'll be 40/7. 
 
        
                    
             
        
        
        
Answer:
4
Step-by-step explanation:
5-1=4