To simplify each of these products, we can start by canceling out common terms in the numerators and denominators.

(-5/8) × (-4/5) × (-3/4) × (-2/3) × (-1/2)
= (5/8) × (4/5) × (3/4) × (2/3) × (1/2)
= (5 × 4 × 3 × 2 × 1)/(8 × 5 × 4 × 3 × 2)
= 120/960
= 1/8

(-7/12) × (-6/7) × (-5/6) × (-4/5) + 2/3
= (7/12) × (6/7) × (5/6) × (4/5) + 2/3
= (7 × 6 × 5 × 4)/(12 × 7 × 6 × 5) + 2/3
= 840/2520 + 2/3
= 1/3 + 2/3
= 1

(-11/15) × (-10/11) × (-9/10) + (-7/9) × (-6/7) + 4/15
= (11/15) × (10/11) × (9/10) + (7/9) × (6/7) + 4/15
= (11 × 10 × 9)/(15 × 11 × 10) + (7 × 6)/(9 × 7) + 4/15
= 990/1650 + 42/63 + 4/15
= 6/10 + 6/9 + 4/15
= 3/5 + 2/3 + 4/15
= 9/15 + 10/15 + 4/15
= 23/15
= 1 8/15

Therefore, the simplified results for each expression are: