= (140 + 7/30) - (138 + 5/12)

= 140 + 7/30 - 138 - 5/12

= 140 - 138 + 7/30 - 5/12

= 2 + (28/120) - (60/120)

= 2 - 32/120

= 2 - 8/30

= 2 - 4/15

= 30/15 - 4/15

= 26/15

Therefore, (140 7/30 - 138 5/12) = 18 1/16 is incorrect. The correct answer is 26/15.