I need help on quadratic equations its so difficult the problem is (x+4) (x-9)=4x can someone please help me

Question

anonymous · Answer

You need to expand the left-hand side and collect like terms.  You will end up with another quadratic which you can factor and solve.

anonymous · Answer

$$(x+4)(x-9)=4x \iff x^2+4x-9x-36=4x \iff x^2-9x-36=0$$which may be factored$$(x+3)(x-12)=0$$

anonymous · Answer

x^2-9 x-36 = 0

anonymous · Answer

Your solutions are then $$x=-3, x=12$$

anonymous · Answer

(x-12)(x+3)

anonymous · Answer

Foil the (x+4)(x-9) which comes out as x^2-5x-36=4x then you subtract 4x on both sides which leaves you with x^2-9x-36=0 then factor it to (x-12)(x+3)=0 x=12    x=-3

anonymous · Answer

Thank you all very much

anonymous · Answer

welcome

anonymous · Answer

Can someone explain to me how to do quadratic equations, im confused?

anonymous · Answer

Look under 'algebra' on this site. In the second column, there should be stuff for the quadratic equation. http://www.khanacademy.org/