he quadratic equation 2x^2 + bx + 18 = x^2 + 9 has a double root. Find all possible values of b.
+2 A quadratic has a double root when the discriminant \(b^2-4ac\) is equal to \(0\).
~
Rearraging the equation grants \(x^2+bx+9=0 \Longrightarrow\) \(a = 1, b = b, c = 9\)
~
\(b^2 - 4(1)(9) = 0\)
\(b^2 = 36\\ b = \boxed{\pm 6}\)
