Respostas

2014-07-22T16:38:41-03:00
(x+5) ( x+3) +x = -15 \\ x^2+ 3x+5x+15= -15 \\ x^2+ 8x+15+15=0 \\ x^2+8x+30=0 \\  \\

Δ = b²- 4*a*c
Δ= 8² - 4.1*15
Δ= 64- 4*15
Δ= 64-60
Δ= 4


x =  \frac{-8+-2}{2}  \\ x'=  \frac{-8+2}{2} = -3 \\ x"=  \frac{-8-2}{2} =  \frac{-10}{2} = -5