Respostas

2013-11-07T22:19:32-02:00
A = (B + b) x h / 2
A = (2x + 3 + x + 4) . 2x + 9 / 2
A = (3x + 4) (2x + 9) / 2
A = 6x² + 27x + 8x + 36
A = 6x² + 35x + 36
6x² + 35x  + 36 = 0
Delta = b² - 4.a.c = 35² - 4 x 6 x 36 = 361
x' = -b + raiz361 / 2 x 6 = -35 + 19 / 12 = -16
x" = -b - raiz361 / 2 x 6 = -35 - 19 / 12 = -54 / 12 = 4,5