Question 397089
                            Solution
Let X1,X2 and X3 denote the three numbers.
=> X1= x
   X2= 5-2*x "5 minus 2 times the first number"
   X3= 6-x   "6 minus the first number"
Therefore the sum of these three numbers should be equal to 49.
=> X1+X2+X3=49
  x+(5-2x)+(6-x)=49
  x+5-2x+6-x    =49
         x-2x-x =49-5-6
             -2x=38
              x =38/-2 which is -19.
So the first number is -19, 
the second number is 5-2x
                    =5-2(-19)
                    =43
and the third number is 6-x
                       =6-(-19)
                       =6+19
                       =25
Thus by checking;
The sum of the three numbers is -19+43+25 which is indeed equal to 49.