Respostas

2013-09-17T13:48:46-03:00
X+5=3x-3
x-3x=-5-3-
2x=-8 /.(-1)
2x=8
x=8/2x=4
-------------
 x^{2} -5x+4=0

D=b^{2}-4.a.c
D=(-5)^{2}-4.1.4
 D=25-16
 D=9
 x_{1,2} = \frac{-b+ -  \sqrt{D} }{2.a}
 x_{1} =  \frac{- (-5) +- \sqrt{9 }{2.1}

 x_{1} =  \frac{5+3}{2}
 x_{1} = \frac{8}{2}
 x_{1} = 4
 x_{2} = \frac{5-3}{2} 
 x_{2} = \frac{2}{2} 
 x_{2} = 1