Question 124354
solve the equation by completing the square. {{{c^2+4c-7=0}}}. my answer was {{{(-2)+-sqrt(11)}}}. am i correct?

<pre><font face = "verdana" size = 4 color = "red"><b>
That's what I got!

Do you have a TI graphing calulator?  If you have 
one you can check your own problems with it easily, 
like this:

On the main screen type either one of your two answers: 

type -2+<font face = "symbol">Ö</font>(11) then press 
these keys: 

STO

XT<font face = "symbol">q</font>n

ENTER

type X²+4X-7 then press:

ENTER

You get the right side of the original equation,
which is 0, so the answer is correct.

Takes a while to get used to checking algebra with a 
graphical calculator, but you get fast at it.

Edwin</pre>