Respostas

2014-08-10T20:46:51-03:00
Aplicando a propriedade distributiva:
(x+4).(x-1) = 7(x+3)
x² -x +4x -4 = 7x + 21
x² + 3x - 4 = 7x + 21
x² - 4x -25 = 0
Delta:
D = (-4)² - 4.1.(-25)
D = 16 + 100
D = 116
Bháskara:
x' = (4 +  \sqrt{116} )/2
x'' = (4 -  \sqrt{116} )/2
2014-08-10T20:57:24-03:00
X + 4 . (x - 1) = 9 - 2 . (x + 3)
x^2 - 1x + 4x - 4 = 9 - 2x + 6
x^2 - 3x - 4 - 9 + 2x - 6 = 0
x^2 - 3x + 2x - 4 - 9 - 6 = 0
x^2 - x - 13 - 6 = 0
x^2 - x - 19 = 0