For the first question x is equal to 4. You get this by adding 7x+2 and 3x and equal it to 42. And then solve algebraically so 10x+2=42 
10x=40 so x equals 4
For the second question x is equal to 6.666 and y is equal to 9 
You get this by getting x is to 10 as 4 is to 6 and you get y by 6 is to y as 4 is to 6 
Hope this helps
        
             
        
        
        
It should be A, it’s the only answer that gives all the available choices or options he could get