Answer:
b = -(4a + c)/4
Explanation:
sum of a, b, and c is five times the sum of a and b,
a + b + c = 5(a + b)
which of the following expresses the value of b in terms of a and c?
a + b + c = 5(a + b)
a + b + c = 5a + 5b
a + c - 5a = 5b - b
-4a + c = 4b
b = -(4a + c)/4