Here basically what you need to do is substitute the values of x given in the table into the equation above the table (y = x - 7):
if x = 3: y = 3 - 7 = -4
if x = -5: y = -5 - 7 = -12
if x = 8: y = 8 - 7 = 1
if x = -9: y = -9 - 7 = -16
if x = 0: y = 0 - 7 = -7