Respostas

2013-11-21T22:47:28-02:00
(2x-1)²-(x+2)=2x
4x ² - 4x + 1 - x + 2 = 2x
4x² - 7x  + 3 = 0

D=  49 - 48 = 1
x =  \frac{7 +- 1}{8}

x' = 1
x'' = 3 / 4



(x-5) . (x-3)-x=5
x²  - 3x - 5x + 15 -x = 5
x²  - 9x + 10 =0

D= 81 - 40 = 41

x=  \frac{9 +-  \sqrt{41} }{2}