Answer:
c - a
Step-by-step explanation:
Given that b-a = c-b = d-c, to find the expression equal to d-b, separate the equations in the manner below
b-a = d-c
and
c-b = d-c
From the first equation, subtract b from both sides such that
b - a - b = d - c -b
-a = d-c -b
Add c to both sides such that
c - a = d-c -b + c
c - a = d - b
Hence d - b is equal to c - a
