Respostas

2014-05-22T22:25:41-03:00
(12+x).(10+x)= 168

12(10) + 12(x) + 10x + x² = 168

120 + 12x + 10x + x² = 168


x² + 22x - 48 = 0

usa Bhaskara.

Δ = b² - 4.a.c

Δ = 22² - 4(1)(-48)=  676

vamos logo tirar essa raiz 676 = 26


x1 = - 22+ 26 / 2  =  2

x2 = -22 - 26 / 2 = - 24


resp : { X= 2   ou  x = - 24}