Quadratic Formula Question #2

http://i.imgur.com/XviXYODh.jpg

The question is #10,

I am really bad at word problems and having to create an equation on my own...

x^2 - 1/2x = 11

That is all I got and I am pretty sure I am wrong, I didn't go further with that equation I made...

The answer to this question is -3.80 and 5.80.

Any help would be great, thanks!

Re: Quadratic Formula Question #2

The question is "subtract a number from half its square", you have subtracted half a number from its square.

Re: Quadratic Formula Question #2

Re: Quadratic Formula Question #2

Let the number be = x

subtract the the number from half its square

It should be : 1/2 x^2 - x

Now proceed to solve.

Re: Quadratic Formula Question #2

1/2x^2 - x - 0 = 0

I got x = 0 and x = 2

Re: Quadratic Formula Question #2

No you have missed out the RHS. The equation is

1/2 x^2 - x = 11

x^2 - 2x - 22=0

This will give you the desired result.

Use quadratic formula OK