Question

Their sum is 54 and difference is 20

Answer 1

x+y =54
x-y =20
x =37 and y = 17

Answer 2

let the numbers be x and y
A.T.Q.,
x + y = 54. .....(i)
&
x - y = 20.......(ii)

On adding both eq. we get:
2x = 74
x = 37
putting value of x = 37 in eq (i), we get;
37 + y = 54
=> y = 54 - 37
=> y = 17

therefore,
x = 37
y = 17

hope it helps u...