this is a simple question but its confused me

heres the question

f(x)= 2 - x^2 where x = -3

is it -7 or is it 11 im confused by the sign change

thanks..

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- Jan 5th 2010, 09:42 AMmike--1988basic algebra help!
this is a simple question but its confused me

heres the question

f(x)= 2 - x^2 where x = -3

is it -7 or is it 11 im confused by the sign change

thanks.. - Jan 5th 2010, 09:46 AMshinhidora
- Jan 5th 2010, 09:46 AMArchie Meade
$\displaystyle 3(3)=3+3+3=9$

$\displaystyle 3(-3)=-3-3-3=-9$

$\displaystyle (-3)(-3)=-[3(-3)]=opposite\ of\ subtract\ 3\ three\ times$

$\displaystyle which\ is\ add\ 3\ three\ times.$

$\displaystyle Hence\ (-3)(-3)=3(3)=9$

$\displaystyle 2-x^2=2-(-3)^2=2-(9)=-7$ - Jan 5th 2010, 09:47 AMbigwave
- Jan 5th 2010, 09:52 AMmike--1988
thanks everyone (Rock)