What are the possible ways to find the roots from a quadratic equation?

quadratic equation where the coefficients of the quadratic equation: ax^2 + bx + c are substituted into the formula: [-b +- (b^2 - 4ac)^0.5] / 2a. The roots are what x equalscompleting the square where the coefficients of the quadratic equation: ax^2 + bx + c are substituted into (x + b/2)^2 + c. The roots are what x equalsplotting it as a graph and where the curve crosses the y axis (x=0), these are your rootsfactorising where the quadratic equation can be rewritten as (ax +- b)(cx +- d). The roots are x = -+b/a and x = -+d/c