3.8 8.57 - (2.8 8.57 + 0.7 * 8.57)

= 32.66 - (22.68 + 6)

= 32.66 - 28.68

= 3.98

So, 3.8 8.57 - (2.8 8.57 + 0.7 * 8.57) is equal to 3.98.