Respostas

2013-11-15T21:30:38-02:00
A² = b² + c²
(x+3)² = (x+1)² + (x+2)²
x² + 6x + 9 = x² + 2x + 1 + x² + 4x + 4
x² - 2x² + 6x - 2x - 4x + 9 - 1 - 4 = 0
-x² + 4 = 0
-x² = -4     [x(-1)]
x² = 4
x = ± \sqrt{4}
x' = + 2
x" = - 2