first number = x
second number = x-3
third number = 2x
x + x-3 + 2x = 53
4x -3 =53
4x -3+3 =53+3
4x = 56
4x/4 = 56/4
x = 14
first number = 14
second number = 14-3
second number = 11
third number = 2x
third number = 2(14)
third number = 28
14 + 11 +28 = 53
53=53