Thread: Solving Quadratic Equation Using Box Factoring

f(x)=6x^2+9x-6

Where does this function intersect the x-axis (i.e. what are the roots or zeroes of f(x))?

Solve by factoring using the Box Method. When I use the method that is shown on this website Factoring Quadratics: The Hard Case for this particular problem I end up with this as my factored down version of the equation.
(6x-3)(3x+6)
But that is wrong because I would end up with 18x^2 instead of 6x^2.

My question is that does using the method on that website to factor down a quadratic work for this equation? If so, could someone tell me what I'm doing wrong.









Thanks

Originally Posted by nordqvist11

f(x)=6x^2+9x-6

Well, first divide by 3; so you get this equation:
2x^2 + 3x - 2 = 0
Easy to factor: (x - 2)(2x + 1)
Now go "box" that...whatever that means

Are you also able to use other methods? ...