Question 4331
Let the number be x and y
as per the question 
x+y = 49  - (eq1)
x-y = 25  - (eq2)

adding eq1 and eq2 we have

x+y = 49  
x-y = 25  
------------
2x  =  74
x = 74/2 = 37 
putting the value in equation 1 we have

37 + y = 49
y = 49-37 = 12

so x = 37 and y = 12  (Ans)