Answer:

c = -1 or -1/2

Step-by-step explanation:

Use polynomial remainder theorem

f(x) = x²-3x+1

a = -2c

remainder = -1

f(a) = a²-3a+1 = -1

solve for a

a1 = 2 or a2 = 1

a1 = -2c1 --> c1 = a1/-2 = 2/-2 = -1

a2 = -2c2 --> c2 = a2/-2 = 1/-2 = -1/2