The roots of the equation x2 + 2x + 9 =0 are imaginary as the discriminant D= 4-36= -32 , which is negative.
As the imaginary roots of a quadratic equation are conjugate to each other, so both the roots of the equations will be common.
So, a/1 = b/2 =c/9
or, a:b:c = 1:2:9