Answer:
C
Step-by-step explanation:
m = 5x - 2
(5x - 2)² + 35x - 14 = -12
(5x - 2)² + 7(5x - 2) = -12
Replace (5x - 2) by m in the equation above
m² + 7m = -12
m² + 7m + 12 = 0