Question 831001
Let the two numbers be x and y.   x+y=77--(1)   and x-y=25--(2)   > x=77-y--(3) then substituate equation 3 into equation 2.  (77-y)-y=25 >77-2y=25 >-2y=25-77 >-2y=-52 (then divid both sides by -2)>  y=26.  To get x,substitute y=26 into equation 1 >x+y=77 >x+26=77 >x=77-26 >x=51.     (x=51 and y=26)