x^2-4x-32=0
2007-02-08 14:01:55 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
When you factor you want two numbers that can multiply to make the last number, -32, and add together to make the middle number, -4. These are -8 and +4. So you factor
(x-8)(x+4) = 0
so x = 8 or 4
The reason why this works is the zero factor property. If you have several things that multiply together to make zero, at least one of those must be 0. So x-8 = 0 gives x = 8, and x + 4 = 0 gives x = -4.
factoring is hard at first, till you understand it and get more practice. Then it gets easier. Here's some links that may help....
http://www.purplemath.com/modules/factquad.htm (go thru all the links, there's about 4 pages)
http://www.wtamu.edu/academic/anns/mps/math/mathlab/col_algebra/col_alg_tut18_polyeq.htm
see also
http://answers.yahoo.com/question/index;_ylt=AmRCG2H08L079xcc7uYIxpTsy6IX?qid=20070116093108AANHvgm
2007-02-08 14:29:57 · answer #1 · answered by Joni DaNerd 6 · 0⤊ 0⤋
It's (x+4)(x-8)=0 If you were to mutiply these two terms you'd get your original equation you typed up.
Then solve x+4=0 which is x= -4
and solve x-8=0 which is x=8
2007-02-08 22:10:21 · answer #2 · answered by angeliquedesjardins 3 · 0⤊ 0⤋
You can solve this one by factoring.
2007-02-08 22:08:34 · answer #3 · answered by raz 5 · 0⤊ 0⤋