To add the two numbers, we first need to convert the mixed numbers to improper fractions.

-5/8 + (-2 6/1) = -5/8 + (-14/5) = -5/8 - 112/40 = -200/40 - 112/40 = -312/40

-4 7/8 + (-3 2/5) = -39/8 + (-17/5) = -195/40 + (-136/40) = -331/40

Therefore, the sum of (-5/8 + (-2 6/1)) + (-4 7/8 + (-3 2/5)) is:

-312/40 + (-331/40) = -643/40

So, (-5/8 + (-2 6/1)) + (-4 7/8 + (-3 2/5)) = -643/40