Respostas

2013-05-04T00:06:00-03:00

x (x+4) + x (x+2) = 2x² + 12
x² + 4x + x² + 2x = 2x² + 12
2x² + 6x = 2x² + 12
2x² - 2x² + 6x = 12
6x = 12
x = 12
        6
x = 2