How to do 8 out of 27

How to do 8 out of 27

8 / 27 △ 7 (2 / 3-1 / 5)
=8 / 27 △ 7 (10 / 15-3 / 15)
=8 / 27 △ 7 / 15
=8 / 27 / 15
=8 / 27 × 15
=40/9