99/5/16 × (-8)
=99×(-8) + 5/16 ×(-8)
= - 794/1/2
42 × (-10/19/21)
= -420 - 42×19/21
= -458
5.2 × 3/8 + 4.625 × 5/1/5 - 3 × 26/5
= 5/1/5 × 3/8 + 4/5/8 × 5/1/5 - 3 × 5/1/5
= 5/1/5 × (3/8 + 4/5/8 - 3)
= 5/1/5 × (5 - 3)
= 5×2 + 1/5 × 2
= 10/2/5
8 × (-4/2/9) × (-0.125) × 3/19
= 8 × 4/2/9 × 1/8 × 3/19
= 38/9 × 3/19
= 2/3
(-5/6 - 3/4 + 7/8) × (-24)
= 5×4 + 3×6 - 7×3
= 20 + 18 - 21
= 17