x^2-7x=3

and

x+8=1-x^2

Dont even know where to begin

Please help..

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- Jul 15th 2007, 11:21 AMgetnaphdQuadradic
x^2-7x=3

and

x+8=1-x^2

Dont even know where to begin

Please help.. - Jul 15th 2007, 01:08 PMCaptainBlack
These are quadratics, rearrange then into standard form then apply the

quadratic formula.

The first can be rearranges to $\displaystyle x^2-7x-3=0$. Now the quadratic

formula tells us that if we have a quadratic $\displaystyle ax^2+bx+c=0$, then:

$\displaystyle

x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}

$

In the current case $\displaystyle a=1,\ b=-7,\ c=-3$, so:

$\displaystyle

x=\frac{7 \pm \sqrt{49+12}}{2}

$

RonL