# algebra help please!

• Jan 13th 2007, 12:15 AM
u.........
Im really stuck right now

evaluate x^2-x for the value of x satisfying

4(x-2)+2=4x-x(2-x)
• Jan 13th 2007, 12:36 AM
earboth
Quote:

Originally Posted by urlostaznbro
Im really stuck right now

evaluate x^2-x for the value of x satisfying

4(x-2)+2=4x-x(2-x)

Hello,

first solve the equation for x:

$4(x-2)+2=4x-x(2-x) \Longleftrightarrow 4x-8+2=4x-2x+x^2$ which simplifies to:

$x^2-2x+6=0\ \Longrightarrow \ x_1=1+2i\ \vee \ x_2=1-2i$

Now plug in these values into the given term:

$(1+2i)^2-(1+2i)=1+4i-4-1-2i=-2+2i$

$(1-2i)^2-(1-2i)=1-4i-4-1+2i=-4-2i$

EB