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LRW
November 13, 2008, 05:56 AM
:banghead: I'm stuck on one problem, I just can't find any factors in it.

112a^2-168a+63

Numbers I've tried:
3
4
6
7
8
9
14
13
15
16
17
18
19
21

sosia
November 13, 2008, 06:23 AM
I suppose it's 112a^2-168a+63 = 0
ECUACIÓN DE SEGUNDO GRADO ax2+bx+c=0
Quadratic ecuation (wikipedia (http://en.wikipedia.org/wiki/Quadratic_equation) or here) (http://www.analyzemath.com/Equations/Quadratic-1.html)
Las soluciones de la ecuación vienen dadas por x=(-b± sqr(b2-4ac))/(2a)
112a^2-168a+63 = 0
--->
a = (+168 ± sqrt(168*168-4*112*63))/(2*112)
a = (+168 ± sqrt(28224-28224))/(224)
a = (+168 ± sqrt(0))/(224)
a = (+168 ± 0))/(224)
a = (+168)/(224)
a= 0,75 aka 3/4

saludos

LRW
November 13, 2008, 06:28 AM
I completely forgot about the quadratic formula, that would have saved me a major headache...

Thank you!

sosia
November 13, 2008, 06:33 AM
de nada :D

Tomisimo
November 13, 2008, 11:10 AM
Moved to the General Chat forum, since the Practice and Homework forum is for Spanish or English language related practice or homework help.