# Quadratic Formula Question #2

• May 6th 2013, 10:02 AM
Mathnood768
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!
• May 6th 2013, 12:04 PM
Shakarri
Re: Quadratic Formula Question #2
The question is "subtract a number from half its square", you have subtracted half a number from its square.
• May 6th 2013, 05:16 PM
Mathnood768
Re: Quadratic Formula Question #2
I'm dumb, I don't know.
• May 6th 2013, 06:41 PM
ibdutt
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.
• May 6th 2013, 09:23 PM
Mathnood768
Re: Quadratic Formula Question #2
1/2x^2 - x - 0 = 0

I got x = 0 and x = 2
• May 6th 2013, 10:00 PM
ibdutt
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