Respostas

2014-08-10T07:36:05-03:00
4x (x + 6) - x² = 5x²
4x² + 24x - x² = 5x²
4x² - x² - 5x² + 24x = 0
-2x² + 24x = 0
-x² + 12x = 0
a = -1
b = 12
c = 0

Δ = b² - 4ac
Δ = (12)² - 4(-1)(0)
Δ = 144

x = -b +- √Δ / 2a
x =  -12 +- 12/ -2

x1 = 0/-2 = 0
x2 = -24/-2 = 12