# Solving Equations

• Jul 11th 2008, 01:37 PM
princess_anna57
Solving Equations
3x^2 - x - 2 = 0

x = 1
Is there another solution to this equation ie another number that can be x?
• Jul 11th 2008, 01:45 PM
Jhevon
Quote:

Originally Posted by princess_anna57
3x^2 - x - 2 = 0

x = 1
Is there another solution to this equation ie another number that can be x?

yes, princess, there is. in fact, quadratics always have two solutions (though there may be a repeated root, but whatever :D)

note that $3x^2 - x - 2 = (3x + 2)(x - 1)$

now for that to equal zero, we must have 3x + 2 = 0 or x - 1 = 0. those give you your two solutions
• Jul 11th 2008, 01:53 PM
Ecirbaf
The other solution
If you get a solution '1' and b^2-4*a*c (=(-1)^2-4*3*-1=25) isn't 0, it does exist another one, c/a( = -2/3).