what are the solutions to the quadratic equation?
x^2-9x+20=0 I started it but got stuck on the last step.

Question

what are the solutions to the quadratic equation? 
x^2-9x+20=0    I started it but got stuck on the last step.

anonymous · Answer

$$x=\frac{ 9\pm \sqrt{1} }{ 2 }$$

this is what I have so far. I just don't know haw to solve for x

anonymous · Answer

@ganibl

anonymous · Answer

It can be rather made simple lets find the factors for 20 whose sum will give us -9

Which I prefer would be -5 and -4 because -5*-4 = 20 and -5 -4 = -9

anonymous · Answer

Now we can simplify the equation as x^2 -5x - 4x + 20

x(x-5) -4(x - 5) (Taking x common from first two terms and -4 common from next two terms)

(x-5) (x - 4)

anonymous · Answer

So now u have solutions x = 5 , 4

anonymous · Answer

so, don't use the quadratic formula ?

anonymous · Answer

We can use it and u will get the same answer we get from this method. Do u want me to show with that too?

anonymous · Answer

yes

anonymous · Answer

Sure -b + sqrt(b^2 - 4ac)/2a

9 + sqrt (81 - 80)/2
9+sqrt(1)/2

9+1/2

10/2 = 5 :) (square root of 1 is 1 :) ) And now u can get the other root I guess :)

anonymous · Answer

I see now, thank you!