Question

revolva em r as seguintes inequacoes a) (1+x)(-2x+1)<0

Answer 1

a) (1 + x) (-2 x + 1 ) < 0
-2 x + 1 + x - 2 x² < 0
-2 x² - 1 x + 1 < 0
Δ = b² - 4 .a.c
Δ = (-1)² - 4 .-2. 1
Δ = 1 + 8
Δ = 9 ⇒√9 = 3
x = - b + ou - 3/2.a
x´= -(-1) + 3/2.-2
x´= 1 + 3/-4
x´= 4/-4 = -1
x´´ = 1 - 3 /-4
x´´ =  -2/-4
x´´ = 1/2

 -1 < x < 1/2