From Equation (I), we found that one solution is x=0. To find other solutions, we will solve Equation (II). Note that this is a quadratic equation. Thus, we will use the Quadratic Formula.
ax^2+bx+c=0 ⇔ x=- b±sqrt(b^2-4ac)/2a
To do so, we first need to identify a, b, and c.
x^2+x-9=0 ⇔ 1x^2+ 1x+( - 9)=0
We see that a= 1, b= 1, and c= - 9. Let's substitute these values into the formula and solve for x.