Answer:
b² - 4ac = 0
Step-by-step explanation:
The nature of the roots of a quadratic equation are determined by the discriminant, that is
• If b² - 4ac > 0 then roots are real and distinct
• If b² - 4ac = 0 then roots are real and equal
• If b² - 4ac < 0 then roots are not real
x = - 3 indicates an equal root, hence b² - 4ac = 0