A quater of two numbers is 16 and three times the difference of the numbers is 30. Calculate the values of the numbers

 
which can be written as 
 

and 

 

or 

 


system: 
x+y=64
x-y=30 


adding equations 
2x=94
x=47 
and so y=47-30=17 


x=47, y=17 

:)