Question

resolvendo-se a ineguação (x-5).(x-2x-15)<0

Answer 1

(x-5).(x-2x-15)<0

x²-2x²-15x-5x+10x+75 < 0
-x²-10x+75 < 0

x+x'=-10
x*x'=-75
x = 5
x' = -15

S = {x $\epsilon \mathbb{R}$ | x < -15 ou x > 5}