Explanation: The general formula of the quadratic equation is: ax²+ bx + c = 0 The given equation is: x² + 3x - 18 = 0 By comparison, we can find that: a = 1 b = 3 c = -18
To get the roots, we will use the quadratic formula shown in the attached image.
By substituting in the equation, we would find that: either x = [tex] \frac{-3 + \sqrt{(3)^2-4(1)(-18)} }{2(1)} = 3[/tex]
or x = [tex] \frac{-3 - \sqrt{(3)^2-4(1)(-18)} }{2(1)} = -6[/tex]
