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# factor the qudratic equation -3X^2-6X+9

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 Question by rint Submitted on 2/17/2004 Related FAQ: [alt.algebra.help] FAQ pointer - read this first Rating: Rate this question: N/A Worst Weak OK Good Great factor the qudratic equation -3X^2-6X+9

 Answer by mathsgirl Submitted on 4/28/2004 Rating: Rate this answer: N/A Worst Weak OK Good Great To factorise a quadratic like this you need to split it into two parts: 1) Multiply the number of x^2 by the constant, i.e. -3*9=-27 2) Find two factors of this number which added together give the number of x, i.e. 3*-9=27 and 3-9=-6 3) Rewrite the quadratic with the x term split up into a sum of these factors, i.e. -3x^2-6x+9=-3x^2+3x-9x+9 4)Factorise the first and second halves separately; -3x^2+3x=3x*(-x)+3x*1=3x(-x+1) and -9x+9=9*(-x)+9*1=9(-x+1) so, -3x^2+3x-9x+9=3x(-x+1)+9(-x+1) 5) Factorise again; in this case, there is a common factor of -x+1 so we can write 3x(-x+1)+9(-x+1)=(3x+9)(-x+1) Hope it helps :-)

 Answer by boygood Submitted on 8/6/2004 Rating: Not yet rated Rate this answer: N/A Worst Weak OK Good Great the answer of that question is easy!! a.-3x^2-6x+9 b.-3x^2-6x-9=0 c.(-3x^2-3)+(-3-9)=0 d.x-3=0   x-3=0 e.x=3     x=3

 Answer by ahsan Submitted on 11/7/2006 Rating: Not yet rated Rate this answer: N/A Worst Weak OK Good Great 2x2 \

 Answer by Narottam Submitted on 6/26/2007 Rating: Not yet rated Rate this answer: N/A Worst Weak OK Good Great 1)let a=-3,b=-6 and c=9 2)multiply c*a=9*-3,f(x)=x^2-6x-27 3)completing square=>x^2-6x+9=27+9(adding 9 both sides) 4)=>(x-3)^2=36 => x=3+-6 =>x=9,-3 5)but the original roots will be-->9/a and  -3/a i.e. 3,-1

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