Use the quadratic formula to solve 7c^2 + 8c + 1 = 0

7c² + 8c + 1 = 0

c = - (8) + / - √ ((8) ² - 4 (7) (1))

2 (7)

c = - 8 + / - √ (64 - 28)

14

c = - 8 + / - √ (36)

14

c = - 8 + / - 6

14

c = - 8 + 6 c = - 8 - 6

14 14

c = 2 c = - 14

14 14

c = ¹/₇ c = 1

The solution is equal to { 1, ¹/₇}.