Respostas

2013-09-08T16:45:36-03:00
X² +  x = 12
x² + x - 12 = 0
baskhara
b² - 4ac => 1 - 4.(-12)(1) = 49, cuja raiz é 7
-b +-7/2 = > -1 + 7 / 2 = 3 
3 + 3² = 3 + 9 = 12

Abs!
2013-09-08T16:51:13-03:00
 x^{2} +x=12\\2 x^{2} =12\\  x^{2} =\frac{12}{2} \\ x^{2} =6\\x= \sqrt{6} \\\\
substituindo x por raiz de 6 pra confirmar a resposta temos:2. (\sqrt{6} )^2=12