Respostas

2013-06-27T23:37:20-03:00

► x² - 4/5x = 1/5 
► x² - 4/5x - 1/5 = 0
► 5x² - 4x - 1 = 0

► FORMULA DE BASKHARA: 

ax² + bx + c = 0

a = 5
b = -4
c = -1

∆² = b² - 4ac = (-4)2 -4.5(-1) = 36
∆ = 6

► x´= -b/2a + ∆/2a = 4/10 + 6/10 = 1
► x´´= -b/2a - ∆/2a = 4/10 - 6/10 = -1/5